Genetics of congenital adrenal hyperplasia

PERSPECTIVE: Treatment with hydrocortisone modified-release capsules in children and adolescents with congenital adrenal hyperplasia: an expert opinion

Recommended treatment for classic congenital adrenal hyperplasia (CAH) in children is hydrocortisone. This therapy is intended to replace cortisol deficiency, but also to reduce the increased production of androgens and their precursors. The aim is to minimize the undesirable side effects of both cortisol deficiency and androgen excess. Short-acting conventional immediate-release hydrocortisone formulations does not mimic physiological diurnal rhythm and often complicate therapy adjustment, mandating frequent administration of often supraphysiological doses, typically 3-4 times daily, including nocturnal dosing. To simulate the physiological diurnal cortisol pattern, a delayed- and sustained-release hydrocortisone preparation has been developed and its efficacy was validated through phase 2 and 3 trials in adult patients. Regulatory approval has been extended to encompass both adult and adolescent patients aged 12 years and older. This manuscript aims to provide treatment principles formulated by two expert centers specialized in pediatric CAH therapy regarding the utilization of recently registered hydrocortisone modified-release capsules in the daily management and stress dosing regimen for adolescents with CAH. It elucidates proposed dosing strategies, therapeutic surveillance protocols and the prospective accumulation of data for the assessment of treatment efficacy during childhood.

Free Cortisol and Free 21-Deoxycortisol in the Clinical Evaluation of Congenital Adrenal Hyperplasia

CONTEXT

Some patients with classic congenital adrenal hyperplasia (CAH) survive without glucocorticoid treatment. Increased precursor concentrations in these patients might lead to higher free (biological active) cortisol concentrations by influencing cortisol-protein binding. In 21-hydroxylase deficiency (21OHD), the most common CAH form, accumulated 21-deoxycortisol (21DF) may further increase glucocorticoid activity. Both mechanisms could explain the low occurrence of symptoms in some patients with untreated classic CAH.

OBJECTIVE

Develop and validate a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for free cortisol and free 21DF to quantify these steroids in patients with untreated classic CAH before and after Synacthen administration, and compare these concentrations to concentrations measured in patients with nonclassic CAH (NCCAH), other forms of adrenal insufficiency (AI), and controls.

METHODS

An LC-MS/MS method to measure free cortisol and free 21DF was developed and validated. Total and free serum concentrations of both cortisol and 21DF were measured in patients with untreated classic CAH (n = 29), NCCAH (n = 5), AI (n = 3), and controls (n = 11) before and 60 minutes after stimulation with Synacthen.

RESULTS

Unstimulated total cortisol concentrations of patients with untreated classic CAH (median 109 nmol/L) were lower than in patients with untreated NCCAH (249 nmol/L, P = .010) and controls (202 nmol/L, P = .016), but free cortisol concentrations were similar. Basal free 21DF concentrations were high in patients with 21OHD (median 5.32 nmol/L) and undetectable in patients with AI and controls (<0.19 nmol/L). After Synacthen administration, free 21DF concentrations increased in patients with 21OHD, while free cortisol concentrations did not change.

CONCLUSION

Free cortisol concentrations in patients with classic CAH were similar to those in controls and patients with NCCAH, indicating comparable cortisol availability. Additionally, patients with 21OHD produce high concentrations of 21DF, possibly explaining the low occurrence of symptoms in some patients with classic 21OHD. Free cortisol and 21DF levels should be considered in evaluating adrenal insufficiency in patients with CAH.

Long-term outcomes of congenital adrenal hyperplasia due to 21-hydroxylase deficiency: a retrospective study from a tertiary care center in Saudi Arabia

Introduction

Data on congenital adrenal hyperplasia (CAH) disorders in the Saudi population are limited. This retrospective study assessed the clinical characteristics ofadolescents and adults with 21-hydroxylase CAH alongside the long-term outcomes of chronic glucocorticoid replacement therapy.

Methods

The study was conducted at the King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. The subjects included patients (aged ≥ 14 years) with 21-hydroxylase CAH, who attended the endocrine clinic between 2019 and 2021.

Results

The study found that among the 108 patients with 21-hydroxylase deficiency considered, predominantly females (66.67%), with a median age of 21 years (IQR: 18-30), 93.51% had the classic salt-wasting form, while 6.49% had the nonsalt-wasting form. Glucocorticoid therapy for the patients included prednisone (46.3%), hydrocortisone (37.97%), and dexamethasone (12.03%). Short stature was observed in 30% of the patients, while obesity affected 35.19%. Among the females, 58.33% had oligomenorrhea. In addition, testicular adrenal rest tumors (TARTs) were detected in 44.44% of the males. Metabolic issues included high cholesterol in 95.65%, with 17.33% exhibiting prediabetics. Genetic testing identified CYP21A2 mutations in all patients tested.

Discussion

short stature, obesity, and menstrual irregularities are highly prevalent in females, whereas TARTs are common in males. Although metabolic and bone health outcomes are generally favorable, the variability in hormonal control and its associated complications underscores the need for individualized glucocorticoid therapy. Continuous monitoring and improved treatment strategies are essential for optimizing the quality of life of patients with CAH.

Two families, two pathways: a case series of 46, XY DSD with 17α-hydroxylase deficiency and isolated 17,20-lyase deficiency due to novel CYB5A variant

OBJECTIVES

17α-hydroxylase and 17,20-lyase are enzymes encoded by the CYP17A1 gene mapped at chromosome 10q, and are required for the synthesis of sex steroids and cortisol. 17α-hydroxylase deficiency causes a decrease in cortisol and androgen with a subsequent overproduction of adrenocorticotrophic hormone (ACTH), gonadotropin, and 11-deoxycorticosterone. However, isolated 17,20-lyase deficiency is a rare condition that results in sex steroid deficiency with normal serum cortisol. This case series aims to report a novel canonical splice site CYB5A variant causing isolated 17,20-lyase deficiency and highlight the utility of steroid metabolomics in diagnosing 17α-hydroxylase and isolated 17,20-lyase deficiencies.

CASE PRESENTATIONS

We describe four patients with ambiguous genitalia who were accurately diagnosed through steroid metabolomics using liquid chromatography- mass spectroscopy (LC-MS). Genetic testing identified a novel homozygous likely pathogenic 5' canonical splice site variant, c.129 + 1G>A in intron 1 of CYB5A gene, resulting in isolated 17, 20 lyase deficiency.

CONCLUSIONS

Here, we report four patients with 46, XY disorder of sexual development (DSD) from two families with 17α-hydroxylase deficiency and isolated 17,20-lyase deficiency due to cytochrome b5 variant with a variable spectrum of under-virilization who had received inadequate treatment for a prolonged period of time due to incorrect diagnosis.

Identification of a Homozygous Variant in the CYP21A2 Gene by Next-Generation Sequencing Analysis of Circulating Cell-Free Fetal DNA

BACKGROUND/OBJECTIVES

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by mutations in the CYP21A2 gene associated with 21-hydroxylase deficiency and increased levels of adrenal androgens. Affected females are at risk of ambiguous genitalia, while affected males show sexual precocity. Here, we present a case of a newborn female patient, characterized by ambiguous genitalia and previously identified as low risk for common aneuploidies by non-invasive prenatal testing (NIPT).

METHODS

We performed a NIPT, which showed a 46, XX genotype, confirmed by karyotype on the newborn's DNA extracted lymphocytes. For clinical suspicion of CAH, we performed reverse dot blot and Multiple Ligation-dependent Probe Amplification (MLPA) of the CYP21A2 gene on the patients and her parents' DNA. Then, we performed on mother's plasma NGS analysis with an in-house developed panel of genes for monogenic diseases, including the CYP21A2 gene.

RESULTS

Reverse dot blot and MLPA detected the presence of the c.290-13A/C>G (I2 splice) mutation in heterozygosity in the parents and in homozygosity in the child, respectively. NGS detected the c.290-13A/C>G (I2splice) mutation in cell-free fetal DNA (cfDNA) in mother's plasma with a variant allele frequency (VAF) of 67% with a fetal fraction (FF) of 5%. This latter suggests the presence of the variant both in the mother and in newborn cfDNA.

CONCLUSIONS

The study reinforces the hypothesis that cfDNA can be used to identify point mutations, small insertions and/or deletions for the diagnosis of monogenic diseases, reducing the number of invasive tests and the risk of early miscarriages. Early detection of mutations in genes causing sexual development disorders could make it possible to start therapy in the womb.

Newborn screening follow-up in Bavaria: height and weight in paediatric patients with congenital adrenal hyperplasia

OBJECTIVES

Auxology is essential for monitoring congenital adrenal hyperplasia (CAH). Data from prospective studies of newborn screening (NBS) are scarce.

METHODS

Analysis of data extracted from a population-based prospective long-term follow-up survey study of children detected through NBS in Bavaria in 1999-2018. The study is based on standardized parent or patient questionnaires, supplemented by medical reports. Height, weight, and treatment data of 146 children/adolescents with classical CAH were analyzed. The entire observation period up to the age of 18 years was completed by 55 patients. Standard Deviation Scores (SDS) for height/body-mass-index (BMI) at different ages and the deviation of the height SDS at age 18 years from the parental target-height SDS were calculated.

RESULTS

Male and female patients with CAH showed different and altered growth patterns, resulting in a median [IQR] SDS deviation from target height of -0.81 [-1.05, -0.41] in males and -0.35 [-0.90, 0.02] in females. BMI-SDS values were significantly (p<0.05) increased in males aged 6-16 years and in females aged 2 and 8-12 years. The average total steroid dose was higher in males (p<0.001). For deviations from target height, significant associations were found with sex (p<0.05) and adherence (p<0.01), but not with mutation group or steroid-dose. For BMI, none of the parameters showed a significant correlation.

CONCLUSIONS

Early treatment after NBS has helped to improve, but not to normalize, the development of height and weight in patients with CAH. Optimizing monitoring and treatment, preferably sex-specific, remains a challenge for clinical practice and research.

Progesterone Metabolism in Digitalis and Other Plants-60 Years of Research and Recent Results

5β-Cardenolides are pharmaceutically important metabolites from the specialized metabolism of Digitalis lanata. They were used over decades to treat cardiac insufficiency and supraventricular tachycardia. Since the 1960s, plant scientists have known that progesterone is an essential precursor of cardenolide formation. Therefore, biosynthesis of plant progesterone was mainly analyzed in species of the cardenolide-containing genus Digitalis during the following decades. Today, Digitalis enzymes catalyzing the main steps of progesterone biosynthesis are known. Most of them are found in a broad range of organisms. This review will summarize the findings of 60 years of research on plant progesterone metabolism with particular focus on the recent results in Digitalis lanata and other plants.

Advocating Targeted Sequential Screening over Whole Exome Sequencing in 21-Hydroxylase Deficiency

OBJECTIVES

Whole exome sequencing (WES) has emerged as the preferred method for diagnosing a range of Mendelian disorders. Nonetheless, the applicability of WES in genetic diagnosis of 21-hydroxylase deficiency (21-OHD) remains uncertain due to the intricacies involved in molecular analysis of the CYP21A2 gene.

METHODS

In this case series, authors report the outcomes of couples or families who underwent WES followed by focused sequential strategy (FSS) targeting CYP21A2 gene hotspot mutations and targeted sequencing of genes associated with Congenital Adrenal Hyperplasia (CAH).

RESULTS

This analysis revealed that WES, when compared to FSS, resulted in six false-negative findings out of seven subjects and one false-positive result. These results were corroborated through validation using Multiplex Ligation-Dependent Probe Amplification (MLPA) and Sanger sequencing.

CONCLUSIONS

One major limitation of exome sequencing lies in target enrichment, which often achieves less than 95% coverage of the regions of interest, potentially leading to false negatives. This challenge is particularly pronounced when deciphering the complex genetics of 21-OHD, characterized by intricate pseudogene-derived rearrangements and gene conversions. Additionally, next-generation sequencing (NGS) analysis of the CYP21A2 gene is not straightforward due to reads aligning to pseudogene regions, necessitating stringent computational pipelines with defined targets. However, simple genotyping assays have shown a high positive yield of pseudogene-derived mutations in over 80% of cases, while targeted NGS can be valuable in subjects with initially negative results. Therefore, WES is not recommended as the primary testing method for 21-OHD and may be better suited for rare forms of CAH once CYP21A2 mutations have been ruled out.

An unusual case of 17-hydroxylase deficiency presenting with short stature

17α-Hydroxylase and 17,20-lyase are enzymes encoded by the CYP17A1 gene and are necessary for the production of cortisol and sex steroids. Females with 17α-hydroxylase deficiency usually present with primary amenorrhea and delayed puberty accompanied by hypertension and electrolyte imbalance. Here, we report the case of a 14-year-old female patient who presented with severe short stature and delayed puberty without any complaint suggestive of 17-hydroxylase enzyme deficiency. Laboratory test results showed low cortisol and dehydroepiandrosterone sulfate (DHEA-S) along with high luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Turner syndrome was excluded after genetic analysis showed a 46,XX karyotype, and 17α-hydroxylase deficiency was diagnosed by detecting a c.1319G>A (p.Arg440His) variation/alternation in the patient's CYP17A1 gene.

The association of infant urinary adrenal steroids with the risk of childhood asthma development

BACKGROUND

Adrenal steroids play important roles in early-life development. However, our understanding of the effects of perinatal adrenal steroids on the development of childhood asthma is incomplete.

OBJECTIVE

To evaluate the associations between early-life adrenal steroid levels and childhood asthma.

METHODS

Participants included the Infant Susceptibility to Pulmonary Infections and Asthma following Respiratory Syncytial Virus Exposure birth cohort children with untargeted urinary metabolomics data measured during early infancy (n = 264) and nasal immune mediator data measured concurrently at age 2 to 6 months (n = 76). A total of 11 adrenal steroid compounds were identified using untargeted metabolomics and 6 asthma-relevant nasal immune mediators from multiplex assays were a priori selected. Current asthma at ages 5 and 6 years was ascertained using validated questionnaires. Associations were tested using logistic and linear regression with confounders adjustment.

RESULTS

Pregnenetriol disulfate (adjusted odds ratio [aOR] = 0.20, 95% CI = 0.06-0.68) and 3a,21-dihydroxy-5b-pregnane-11,20-dione-21-glucuronide (aOR = 0.34, 95% CI = 0.14-0.75) were inversely associated with childhood asthma at 5 and 6 years after multiple testing adjustment. There was a significant interaction effect of pregnanediol-3-glucuronide by biological sex assigned at birth (aOR = 0.11, 95% CI = 0.02-0.51, for those with female sex) on childhood asthma. Pregnenetriol disulfate was inversely associated with granulocyte-macrophage colony-stimulating factor (β = -0.45, q-value = 0.05). 3a,21-dihydroxy-5b-pregnane-11,20-dione 21-glucuronide was inversely associated with interleukin [IL]-4 (β = -0.29, q-value = 0.02), IL-5 (β = -0.35, q-value = 0.006), IL-13 (β = -0.26, q-value = 0.02), granulocyte-macrophage colony-stimulating factor (β = -0.35, q-value = 0.006), and fibroblast growth factor-β (β = -0.24, q-value = 0.01) after multiple testing adjustment.

CONCLUSION

The inverse association between adrenal steroids downstream of progesterone and 17-hydroxypregnenolone and the odds of childhood asthma and nasopharyngeal type 2 immune biomarkers suggest that increased early-life adrenal steroids may suppress type 2 inflammation and protect against the development of childhood asthma.

CYP21A2 Intron 2 Genetic Variants Might Be Associated with the Clinical Characteristics of Women with PCOS

AIMS

Pathogenic variants in the CYP21A2 gene are related to the classic and non-classic forms of congenital adrenal hyperplasia (CAH). However, the role of CAH carrier status in the clinical presentation of polycystic ovarian syndrome (PCOS) is still unclear. Moreover, the possible associations of different CYP21A2 gene polymorphisms with metabolic and reproductive abnormalities in PCOS have not been investigated. Therefore, the present study aims to examine the prevalence of the most common CYP21A2 pathogenic variant IVS2-13A/C>G (c.293-13A/C>G) in Eastern European women with PCOS and to evaluate the associations between common intron 2 genetic polymorphisms and the clinical symptoms of the patients.

METHODS

Sixty consecutively recruited women with PCOS were genotyped for the CYP21A2 intron 2 IVS2-13A/C>G genetic variant. Additionally, CYP21A2 intron 2 polymorphic variants rs6453 (c.293-44G>T), rs6451 (c.293-67C>A/G), rs369651496 (c.293-104del), and rs6474 (c.308G>A/p.R103L) were tested and described. The clinical and hormonal characteristics were compared in women with PCOS and with polymorphic and wild-type genotypes.

RESULTS

The heterozygous CYP21A2 pathogenic variant IVS2-13A/C>G was found in one of the investigated PCOS patients (1.67%) with a non-hyperandrogenic type of PCOS. The presence of the rs6453 (c.293-44G>T) T-allele was associated with increased levels of DHEAS (15.18 vs. 9.14 µmol/L, p = 0.003) compared to the wild-type genotype in the investigated group. The rs6451 (c.293-67C>A/G) minor alleles were associated with an earlier age of menarche in the patients (12.0 vs. 13.0 years, p = 0.007). The polymorphic rs369651496 minor 6G allele was related to a better lipid profile in the women with PCOS, while the rs6474 variant modulated the blood pressure of the patients.

CONCLUSIONS

The presence of CYP21A2 genetic minor alleles of rs6467 (IVS2-13A/C, c.293-13A/C), rs6453 (c.293-44G>T), rs6451 (c.293-67C>A/G), rs369651496 (c.293-104del), and rs6474 (c.308G>A/p.R103L) might modulate the adrenal androgens, age of menarche, and metabolic features in women with PCOS. Further studies on 21-hydroxylase genetic variants (pathogenic and polymorphisms) in different ethnic groups might help reveal the influence of adrenal steroidogenesis on PCOS development, clinical manifestations, and lifelong cardiovascular risks.

Non-classical animal models for studying adrenal diseases: advantages, limitations, and implications for research

The study of adrenal disorders is a key component of scientific research, driven by the complex innervation, unique structure, and essential functions of the adrenal glands. This review explores the use of non-traditional animal models for studying congenital adrenal hyperplasia. It highlights the advantages, limitations, and relevance of these models, including domestic ferrets, dogs, guinea pigs, golden hamsters, pigs, and spiny mice. We provide a detailed analysis of the histological structure, steroidogenesis pathways, and genetic characteristics of these animal models. The morphological and functional similarities between the adrenal glands of spiny mice and humans highlight their potential as an important avenue for future research.

Congenital Adrenal Hyperplasia with Combined 21-hydroxylase deficiency and 17α-hydroxylase/17,20-lyase deficiency: An undervirilized male

21-hydroxylase deficiency stands as the most prevalent form of congenital adrenal hyperplasia, primarily resulting from mutations in the CYP21A2 gene. On the other hand, mutations within the CYP17A1 gene lead to 17α-hydroxylase/17,20-lyase enzyme deficiencies. The scarcity of 17-OH deficiency is noteworthy, accounting for less than 1% of all congenital adrenal hyperplasia cases. The male patient, born from a first-degree cousin marriage, exhibited several symptoms, including left undescended testis, micropenis, penile chord, left sensorineural hearing loss, and gynecomastia. He reported micropenis as a concern at the age of 13.5 years. His hormone profile revealed high levels of serum 17-hydroxyprogesterone, progesterone, and pregnenolone. In this case with a 46 XY karyotype, suspicions arose regarding Cytochrome P450 oxidoreductase deficiency due to ambiguous genitalia and an atypical hormone profile. Analysis unveiled two distinct homozygous and pathogenic variants in the CYP21A2 and CYP17A1 genes. Notably, mineralocorticoid precursors escalated, while cortisol and sex steroid precursors decreased during the high (250 mcg) dose ACTH stimulation test. The mutation c.1169C > G (p.Thr390Arg) in CYP17A1, which is the second documented case in literature, stands out due to its unique set of accompanying features. Mutations occurring in CYP21A2 and CYP17A1 result in complete or partial enzyme deficiencies, and the detection of homozygous mutations in two different enzyme systems within the steroidogenic pathway is noteworthy.

Prenatal diagnosis and in utero treatment of congenital adrenal hyperplasia: An up-to-date comprehensive review

Congenital adrenal hyperplasia (CAH) is a term that encompasses a wide range of conditions that affect the adrenals. Diagnosis and treatment before birth are important as irreparable birth defects can be avoided, decreasing the need for surgical intervention later in life, especially regarding genitalia anomalies. Although early implementation of dexamethasone in the prenatal treatment of CAH has been controversial, there is recent evidence that this treatment can reduce long-term complications.

Targeted long-read sequencing for comprehensive detection of CYP21A2 mutations in patients with 21-hydroxylase deficiency

BACKGROUND

21-Hydroxylase deficiency (21-OHD) is caused by pathogenic CYP21A2 variations. CYP21A2 is arranged in tandem with its highly homologous pseudogene CYP21A1P; therefore, it is prone to mismatch and rearrangement, producing different types of complex variations. There were few reports on using only one method to detect different CYP21A2 variants simultaneously.

AIMS

Targeted long-read sequencing method was used to detect all types of CYP21A2 variants in a series of patients with 21-OHD.

METHODS

A total of 59 patients with 21-OHD were enrolled from Peking Union Medical College Hospital. Long-range locus-specific PCR and long-read sequencing (LRS) were performed to detect the pathogenic variants in CYP21A2.

RESULTS

Copy-number variants of CYP21A2 were found in 25.4% of patients, including 5.1% with 3 copies of CYP21A2, 16.9% with 1 copy of CYP21A2, and 3.4% with 0 copy of CYP21A2. The remaining 74.6% of patients had 2 copies of CYP21A2. Pathogenic variants were identified in all 121 alleles of 59 patients. Specifically, single-nucleotide variants and small insertions/deletions (< 50 bp) were detected in 79 alleles, of which conversed from CYP21A1P were detected in 63 alleles, and rare variants were found in the other 16 alleles. Large gene conversions (> 50 bp) from pseudogene were detected in 10 alleles, and different chimeric genes (CYP21A1P/CYP21A2 or TNXA/TNXB) formed by large deletions were detected in 32 alleles. Of all variants, p.I173N was the most common variant (19.0%).

CONCLUSIONS

Our study demonstrated that targeted long-read sequencing is a comprehensive method for detecting CYP21A2 variations, which is helpful for genetic diagnosis in 21-OHD patients.

Rare nonclassic type of Congenital adrenal hyperplasia due to 21-hydroxylase deficiency and genotype-phenotypic correlation

Objective

To explore the correlation between different CYP21A2 pathogenic gene mutations and clinical phenotypes in Congenital adrenal hyperplasia (CAH) patients. Moreover, combined with the specific phenotypes of patients in the clinic, diagnosis and treatment suggestions should be made for CAH patients.

Methods

In this study, a genetic status of a Chinese family in three generations of 21-hydroxylase deficiency was comprehensively presented, and the pathogenic genes in the family were found and traced in detail. We measured CYP21A2 gene in this family by Sanger sequencing and MLPA. The trophoblast cells of female proband's embryos were detected by PGT-M which used Copy-Number Variations of a Single Human Cell and high throughput sequencing. The CYP21A2 gene mutation site in each embryo were detected by Sanger sequencing, whole genome sequencing and single nucleotide polymorphism (SNP).

Results

There are many related pathogenic genes of CAH in this family. The female proband showed a compound heterozygous mutation in the CYP21A2 gene, including a CYP21A1P/A2 fusion gene (CH-8) (classical phenotype) and a new mutation c.1034T > C (p. L354S) (unknown clinical significance). In the proband's family, a heterozygous gene mutation of c.1034T > C and a CYP21A1P/A2 fusion gene (CH-8) was carried by her father and mother, respectively. Meanwhile, the husband of the proband also has a genetic family with related disease. Both the husband and his father carried the CYP21A2 gene c.844G > T heterozygous mutation, while his mother had no related mutation in the CYP21A2 gene. Furthermore, PGTM gene detection was carried out on the four blastocysts of the proband's offspring through IVF. The results showed that embryos T1, T2 and T4 all carried CYP21A1P/A2 fusion gene (CH-8), as well as embryo T3 carried c.1034T > C heterozygous mutation of maternal origin.

Conclusion

This case is a family report showing a complete genetic map of the proband and her family, describing the genetic process of different pathogenic genes in detail and clearly corresponding to the patient's different phenotypes. It is speculated that the pathogenesis of CAH is caused by different mutations in the CYP21A2 gene and their interactions, which may affect the different phenotypes of CAH patients.

Congenital Adrenal Hyperplasia - A Comprehensive Review of Genetic Studies on 21-Hydroxylase Deficiency from India

Congenital adrenal hyperplasia (CAH) comprises a heterogeneous group of autosomal recessive disorders impairing adrenal steroidogenesis. Most cases are caused by mutations in the CYP21A2 gene resulting in 21-hydroxylase (21-OH) deficiency (21-OHD). The genetics of 21-OH CAH is complexed by a highly homologous pseudogene CYP21A1P imposing several limitations in the molecular analysis. Therefore, genetic testing is still not a part of routine CAH diagnosis and is mainly dependent on 17-hydroxy progesterone (OHP) measurements. There are very few reports of CYP21A2 gene analysis from India and there is no comprehensive review available on genetic testing and the spectrum of CYP21A2 mutations from the country. This review focuses on the molecular aspects of 21-OHD and the genetic studies on CYP21A2 gene reported from India. The results of these studies insist the compelling need for large-scale CYP21A2 genetic testing and newborn screening (NBS) in India. With a high disease prevalence and consanguinity rates, robust and cost-effective genetic testing for 21-OH CAH would enable an accurate diagnosis in routine clinical practice. Whereas establishing affordable genotyping assays even in secondary care or resource-poor settings of the country can identify 90% of the mutations that are pseudogene derived, initiatives on reference laboratories for CAH across the nation with comprehensive genetic testing facilities will be beneficial in those requiring extended analysis of CYP21A2 gene. Further to this, incorporating genetic testing in NBS and carrier screening programmes will enable early diagnosis, better risk assessment and community-based management.

Congenital Adrenal Hyperplasia

We describe congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, which is the most common primary adrenal insufficiency in children and adolescents. In this comprehensive review of CAH, we describe presentations at different life stages depending on disease severity. CAH is characterized by androgen excess secondary to impaired steroidogenesis in the adrenal glands. Diagnosis of CAH is most common during infancy with elevated 17-hydroxyprogesterone levels on the newborn screen in the United States. However, CAH can also present in childhood, with late-onset symptoms such as premature adrenarche, growth acceleration, hirsutism, and irregular menses. The growing child with CAH is treated with hydrocortisone for glucocorticoid replacement, along with increased stress doses for acute illness, trauma, and procedures. Mineralocorticoid and salt replacement may also be necessary. Although 21-hydroxylase deficiency is the most common type of CAH, there are other rare types, such as 11β-hydroxylase and 3β-hydroxysteroid dehydrogenase deficiency. In addition, classic CAH is associated with long-term comorbidities, including cardiometabolic risk factors, impaired cognitive function, adrenal rest tumors, and bone health effects. Overall, early identification and treatment of CAH is important for the pediatric patient.

Landscape of Adrenal Tumours in Patients with Congenital Adrenal Hyperplasia

Our aim is to update the topic of adrenal tumours (ATs) in congenital adrenal hyperplasia (CAH) based on a multidisciplinary, clinical perspective via an endocrine approach. This narrative review is based on a PubMed search of full-length, English articles between January 2014 and July 2023. We included 52 original papers: 9 studies, 8 case series, and 35 single case reports. Firstly, we introduce a case-based analysis of 59 CAH-ATs cases with four types of enzymatic defects (CYP21A2, CYP17A1, CYP17B1, and HSD3B2). Secondarily, we analysed prevalence studies; their sample size varied from 53 to 26,000 individuals. AT prevalence among CAH was of 13.3-20%. CAH prevalence among individuals with previous imaging diagnosis of AT was of 0.3-3.6%. Overall, this 10-year, sample-based analysis represents one of the most complex studies in the area of CAH-ATs so far. These masses should be taken into consideration. They may reach impressive sizes of up to 30-40 cm, with compressive effects. Adrenalectomy was chosen based on an individual multidisciplinary decision. Many tumours are detected in subjects with a poor disease control, or they represent the first step toward CAH identification. We noted a left lateralization with a less clear pathogenic explanation. The most frequent tumour remains myelolipoma. The risk of adrenocortical carcinoma should not be overlooked. Noting the increasing prevalence of adrenal incidentalomas, CAH testing might be indicated to identify non-classical forms of CAH.

Hormonal control during infancy and testicular adrenal rest tumor development in males with congenital adrenal hyperplasia: a retrospective multicenter cohort study

IMPORTANCE

Testicular adrenal rest tumors (TARTs), often found in male patients with congenital adrenal hyperplasia (CAH), are benign lesions causing testicular damage and infertility. We hypothesize that chronically elevated adrenocorticotropic hormone exposure during early life may promote TART development.

OBJECTIVE

This study aimed to examine the association between commencing adequate glucocorticoid treatment early after birth and TART development.

DESIGN AND PARTICIPANTS

This retrospective multicenter (n = 22) open cohort study collected longitudinal clinical and biochemical data of the first 4 years of life using the I-CAH registry and included 188 male patients (median age 13 years; interquartile range: 10-17) with 21-hydroxylase deficiency (n = 181) or 11-hydroxylase deficiency (n = 7). All patients underwent at least 1 testicular ultrasound.

RESULTS

TART was detected in 72 (38%) of the patients. Prevalence varied between centers. When adjusted for CAH phenotype, a delayed CAH diagnosis of >1 year, compared with a diagnosis within 1 month of life, was associated with a 2.6 times higher risk of TART diagnosis. TART onset was not predicted by biochemical disease control or bone age advancement in the first 4 years of life, but increased height standard deviation scores at the end of the 4-year study period were associated with a 27% higher risk of TART diagnosis.

CONCLUSIONS AND RELEVANCE

A delayed CAH diagnosis of >1 year vs CAH diagnosis within 1 month after birth was associated with a higher risk of TART development, which may be attributed to poor disease control in early life.

Lessons Learned from 17 Years of Multidisciplinary Care for Differences of Sex Development Patients at a Single Indonesian Center

BACKGROUND

Our multidisciplinary team (MDT) is a large specialized team based in Semarang, Indonesia, that cares for a wide variety of pediatric and adult individuals with differences of sex development (DSD) from across Indonesia. Here, we describe our work over the last 17 years.

METHODS

We analyzed phenotypic, hormonal, and genetic findings from clinical records for all patients referred to our MDT during the period 2004-2020.

RESULTS

Among 1,184 DSD patients, 10% had sex chromosome DSD, 67% had 46,XY DSD, and 23% had 46,XX DSD. The most common sex chromosome anomaly was Turner syndrome (45,X) (55 cases). For patients with 46,XY DSD under-masculinization was the most common diagnosis (311 cases), and for 46,XX DSD, a defect of Müllerian development was most common (131 cases) followed by congenital adrenal hyperplasia (CAH) (116 cases). Sanger sequencing, MLPA, and targeted gene sequencing of 257 patients with 46,XY DSD found likely causative variants in 21% (55 cases), with 13 diagnostic genes implicated. The most affected gene codes for the androgen receptor. Molecular analysis identified a diagnosis for 69 of 116 patients with CAH, with 62 carrying variants in CYP21A2 including four novel variants, and 7 patients carrying variants in CYP11B1. In many cases, these genetic diagnoses influenced the clinical management of patients and their families.

CONCLUSIONS

Our work has highlighted the occurrence of different DSDs in Indonesia. By applying sequencing technologies as part of our clinical care, we have delivered a number of genetic diagnoses and identified novel pathogenic variants in some genes, which may be clinically specific to Indonesia. Genetics can inform many aspects of DSD clinical management, and while many of our patients remain undiagnosed, we hope that future testing may provide answers for even more.

Clinical Features of Unrecognized Congenital Adrenal Hyperplasia Due to 17α-hydroxylase Deficiency Since Adolescence: A Case Report

The majority of patients with congenital adrenal hyperplasia (CAH) present with a deficiency of 21-hydroxylase or 11-beta-hydroxylase, which account for 90% and 7% of cases, respectively. However, CAH due to 17α-hydroxylase deficiency (17OHD) is an extremely rare form of CAH (<1% of all CAH cases) that leads to a deficiency of cortisol and sex steroids, along with features of aldosterone excess. This is a case of a 51-year-old single female who was referred to us for the evaluation of new-onset hypertension and hypokalaemia of one-year duration. She was born out of a second-degree consanguineous marriage and reared as a female. She was diagnosed to have testicular feminization syndrome when she presented with a history of primary amenorrhea, absence of secondary sexual characteristics, and bilateral labial swellings at pubertal age. Subsequently, she underwent gonadectomy at the age of 16. Due to the presence of hypertension, metabolic alkalosis and bilaterally enlarged adrenals on CT scan, 46, XY disorders of sexual development (DSD) was considered. A karyotype confirmed the presence of 46, XY chromosomal sex, and genetic analysis revealed a mutation in the CYP17A1 gene, thus confirming the diagnosis of 17α-hydroxylase deficiency.

Clinical Update on Congenital Adrenal Hyperplasia: Recommendations from a Multidisciplinary Adrenal Program

Congenital adrenal hyperplasia (CAH) is a common genetic disorder in endocrinology, especially its milder clinical presentation, often caused by a partial or total deficiency of the 21-hydroxylase enzyme located in the adrenal cortex. CAH is characterized by the overproduction of androgen, along with variable degrees of cortisol and aldosterone deficiency. The age at diagnosis can provide some information about underlying mutations, with those diagnosed at birth/early infancy more likely to have severe enzymatic defects, which may include adrenal insufficiency, sexual development disorders, short stature in adulthood, hirsutism, and a higher risk for metabolic syndrome and infertility. Non-classic CAH, a milder form of CAH, is usually manifested later in life and is a common differential diagnosis of Polycystic Ovary Syndrome and should be actively evaluated during initial studies of clinical or biochemical hyperandrogenism. The main goals of CAH treatment are hormone supplementation for severe cases, controlling adrenal androgen overproduction to minimize long-term side effects, managing fertility and genetic counseling, and optimizing patients' quality of life.

Cost-effective genotyping for classical congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) in resource-poor settings: multiplex ligation probe amplification (MLPA) with/without sequential next-generation sequencing (NGS)

PURPOSE

Genotyping of classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is becoming increasingly significant beyond prenatal counseling in the current era of emerging gene therapy/editing technologies. While the knowledge of common variants helps in designing cost-effective genotyping strategies, limited data are currently available from the Indian subcontinent, especially South India, mainly due to financial constraints. The aim of this study is to assess the genotype of individuals with classic CAH from a South Indian cohort in a cost-effective manner.

METHODS

The genotypes of 46 unrelated subjects with classic CAH were studied through initial multiplex ligation-dependent probe amplification (MLPA) using the SALSA MLPA Probe-mix P050 CAH (MRC Holland). Next-generation sequencing (NGS) was done in 10 subjects, as their MLPA was either negative or showed heterozygous variants.

RESULTS

The common variants observed in our study population of 46 subjects were large deletions (35.8%), intron 2 variant [c.293-13A/C > G] (35.8%), 8 bp del [c.332_339del p.(Gly111Valfs*21)] (7.7%), and R356W [c.1069 C > T p.(Arg357Trp)] (6.6%). MLPA alone detected pathogenic variants in 78.2% of the initial study samples (36/46). Sequential NGS resulted in a 100% detection rate in our study population.

CONCLUSION

MLPA appears to be an effective first genotyping modality for this South Indian cohort due to the high prevalence of large deletions and common variants. MLPA as a first initial screening genotyping test with sequential NGS when required may be a cost-effective and highly sensitive approach to CYP21A2 genotyping in our part of the world and in resource-poor settings.

Pregnancy in a woman with congenital adrenal hyperplasia with 11-beta-hydroxylase deficiency: A case report

Background

Successful pregnancy with congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency is an extremely rare condition. Only two cases have been reported in the literature.

Methods and results

Described here is a 30-year-old woman diagnosed as a neonate with congenital adrenal hyperplasia related to 11-beta-hydroxylase deficiency classic type, who subsequently underwent clitoral resection and vaginoplasty. She was started on lifelong steroid therapy after surgery. She developed hypertension at 11 years of age and was on antihypertensive therapy from then on. In later life, she underwent division of vaginal scar tissue and perineal refashioning. She spontaneously conceived but her pregnancy was complicated by severe pre-eclampsia and delivery was required at 33 weeks of gestation by cesarean section. A healthy male infant was delivered.

Conclusion

Management of these women is similar to those with more common causes of congenital adrenal hyperplasia, with careful monitoring throughout pregnancy for complications such as gestational diabetes, gestational hypertension, and intrauterine growth restriction.

Mutation distributions among patients with congenital adrenal hyperplasia from five regions of Brazil: a systematic review

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is an autosomal recessive disorder caused by CYP21A2 gene mutations, and its molecular diagnosis is widely used in clinical practice to confirm the hormonal diagnosis. Hence, considering the miscegenation of the Brazilian population, it is important to determine a mutations panel to optimise the molecular diagnosis. The objective was to review the CYP21A2 mutations' distribution among Brazilian regions. Two reviewers screened Brazilian papers up to February 2020 in five databases. The pair-wise comparison test and Holm method were used in the statistical analysis. Nine studies were selected, comprising 769 patients from all regions. Low proportion of males and salt-wasters was identified in the North and Northeast regions, although without significant difference. Large gene rearrangements also had a low frequency, except in the Center-West and South regions (p < 0.05). The most frequent mutations were p.I172N, IVS2-13A/C>G, p.V281L and p.Q318X, and significant differences in their distributions were found: p.V281L was more frequent in the Southeast and p.Q318X in the Center-West and Northeast regions (p < 0.05). Thirteen new mutations were identified in 3.8%-15.2% of alleles, being more prevalent in the North region, and six mutations presented a founder effect gene. Genotype-phenotype correlation varied from 75.9%-97.3% among regions. The low prevalence of the salt-wasting form, affected males and severe mutations in some regions indicated pitfalls in the clinical diagnosis. The good genotype-phenotype correlation confirms the usefulness of molecular diagnosis; however, the Brazilian population also presents significant prevalence of novel mutations, which should be considered for a molecular panel.

Genetic and clinical characteristics including occurrence of testicular adrenal rest tumors in Slovak and Slovenian patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

OBJECTIVE

To analyze the mutational spectrum, clinical characteristics, genotype-phenotype correlations, testicular adrenal rests tumor prevalence, and role of neonatal screening in congenital adrenal hyperplasia (CAH) patients from Slovakia and Slovenia.

DESIGN AND METHODS

Data were obtained from 104 patients with CAH registered in Slovak and Slovenian databases. Low-resolution genotyping was performed to detect the most common point mutations. To detect deletions, conversions, point mutations, or other sequence changes in the CYP21A2 gene, high-resolution genotyping was performed. Genotypes were classified according to residual 21-hydroxylase activity (null, A, B, C).

RESULTS

64% of the individuals had the salt-wasting form (SW-CAH), 15% the simple virilizing form (SV-CAH), and 21% the non-classic (NC-CAH). CYP21A2 gene deletion/conversion and c.293-13A/C>G pathogenic variant accounted together for 55.5% of the affected alleles. In SV-CAH p.Ile172Asn was the most common pathogenic variant (28.13%), while in NC-CAH p.Val282Leu (33.33%), CYP21A2 gene deletion/conversion (21.43%), c.293-13A/C>G (14.29%), Pro30Leu (11.90%). The frequency of alleles with multiple pathogenic variants was higher in Slovenian patients (15.83% of all alleles). Severe genotypes (0 and A) correlated well with the expected phenotype (SW in 94.74% and 97.3%), while less severe genotypes (B and C) correlated weaklier (SV in 50% and NC in 70.8%). The median age of SW-CAH patients at the time of diagnosis was 6 days in Slovakia vs. 28.5 days in Slovenia (p=0.01). Most of the Slovak patients in the cohort were detected by NBS. (24 out of 29). TARTs were identified in 7 out of 24 male patients, of whom all (100%) had SW-CAH and all had poor hormonal control. The median age at the diagnosis of TARTs was 13 years.

CONCLUSION

The study confirmed the importance of neonatal screening, especially in the speed of diagnosis of severe forms of CAH. The prediction of the 21-OH deficiency phenotype was reasonably good in the case of severe pathogenic variants, but less reliable in the case of milder pathogenic variants, which is consistent compared to data from other populations. Screening for TARTs should be realized in all male patients with CAH, since there is possible remission when identified early.

A Novel Homozygous Pathogenic Variant in CYP11B1 in a Female Iranian Patient with 11B Hydroxylase Deficiency

Objective

Congenital adrenal hyperplasia (CAH) addresses a number of autosomal recessive disorders characterized by the enzyme defects in steroid hormones biosynthesis. The second common form of CAH is caused by mutations in the CYP11B1 gene. Here, we reveal a novel mutation in the CYP11B1 gene related to the 11βOHD phenotype.

Methods and Results

Sequence analysis of the CYP11B1 gene in a 19-year-old Iranian woman with the 11βOHD phenotype was performed. In silico analysis and molecular docking were done. A novel missense homozygous variant c.1351C &gt; T (p.L451F) in the CYP11B1 gene was identified in the patient and, according to American College of Medical Genetics and Genomics criteria, was categorized as likely pathogenic. Protein docking showed destructive effects of the variant on the CYP11B1 protein-ligand interactions.

Conclusion

This study broadens the CYP11B1 mutation spectrum and introduces the novel p.L451F likely pathogenic variant leading to destructive effects on protein-ligand interactions. Our results provide reliable information for genetic counseling and molecular diagnostics of CAH.

Co-Occurrence of a Pathogenic HSD3B2 Variant and a Duplication on 10q22.3-q23.2 Detected in Newborn Twins with Salt-Wasting Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders caused by enzyme deficiencies required for cortisol biosynthesis in the adrenal cortex. The majority of CAH are due to the deficiency of the 21-hydroxylase enzyme, while 3β-hydroxysteroid dehydrogenase type 2 deficiency accounts for less than five percent of all CAH cases. We report two Moroccan twins from a spontaneous triplet pregnancy. The 46,XY newborn exhibited a disorder of sexual differentiation (DSD) with hypo virilization, while the 46,XX newborn had normal female external genitalia. In the first week of life, they showed hyponatremia and primary adrenal insufficiency with a slight 17OHP elevation and increased DHEAS and renin levels. The aCGH-SNP analysis disclosed a 8.36 Mb long contiguous stretch of homozygosity (LCSH) on chromosome 1p13.2-p11.2 including the candidate HSD3B2 gene, a LCSH of 7.3 Mb on 14q31.1-q32.11, and a 7 Mb duplication on 10q22.3-q23.2. Clinical exome sequencing revealed the biallelic c.969T > G (p.Asn323Lys) HSD3B2, likely pathogenic, variant in both of the affected twins. This case emphasizes the importance of a prompt molecular diagnosis performed through the combination of aCGH and clinical exome, both for establishment of correct therapy and for follow-up, as the newborns also carry a genomic rearrangement with possible clinical implications.

Congenital adrenal hyperplasia. Role of dentist in early diagnosis

Congenital adrenal hyperplasia (CAH) is a genetic disorder characterized by an impairment of steroid synthesis due to an altered production of 21-hydroxylase enzyme. Corticoid hormones are involved in the development and functioning of many organs. The aim of the present study was to review the international literature to collect data regarding oral manifestations of CAH. A review of the literature describing oral features of patients affected by CAH was performed using electronic databases (PubMed and Scopus). The data about number of patients, form of CAH, and oral findings were extracted and analyzed. Seven studies were included in the final analysis. The principal findings reported regarded an advanced dental development observed in patients with CAH. One paper reported amelogenesis imperfecta and periodontal issues. The dentist could be the first specialist involved in the CAH syndrome diagnosis, identifying the characteristic features described above, especially for the classical simple virilizing and non-classical form.

Scalable detection of technically challenging variants through modified next-generation sequencing

BACKGROUND

Some clinically important genetic variants are not easily evaluated with next-generation sequencing (NGS) methods due to technical challenges arising from high- similarity copies (e.g., PMS2, SMN1/SMN2, GBA1, HBA1/HBA2, CYP21A2), repetitive short sequences (e.g., ARX polyalanine repeats, FMR1 AGG interruptions in CGG repeats, CFTR poly-T/TG repeats), and other complexities (e.g., MSH2 Boland inversions).

METHODS

We customized our NGS processes to detect the technically challenging variants mentioned above with adaptations including target enrichment and bioinformatic masking of similar sequences. Adaptations were validated with samples of known genotypes.

RESULTS

Our adaptations provided high-sensitivity and high-specificity detection for most of the variants and provided a high-sensitivity primary assay to be followed with orthogonal disambiguation for the others. The sensitivity of the NGS adaptations was 100% for all of the technically challenging variants. Specificity was 100% for those in PMS2, GBA1, SMN1/SMN2, and HBA1/HBA2, and for the MSH2 Boland inversion; 97.8%-100% for CYP21A2 variants; and 85.7% for ARX polyalanine repeats.

CONCLUSIONS

NGS assays can detect technically challenging variants when chemistries and bioinformatics are jointly refined. The adaptations described support a scalable, cost-effective path to identifying all clinically relevant variants within a single sample.

Allele-specific and multiplex PCR based tools for cost-effective and comprehensive genetic testing in Congenital Adrenal Hyperplasia

Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive disorder due to enzyme defects in adrenal steroidogenesis. Several genes code for these enzymes, out of which mutations in the CYP21A2 gene resulting in 21 hydroxylase deficiency, contribute to the most common form of CAH. However, pseudogene imposed challenges complicate genotyping CYP21A2 gene, and there is also a lack of comprehensive molecular investigations in other genetic forms of CAH in India. Here, we describe a cost-effective, highly specific, and sensitive Allele Specific PCR (ASPCR) assay designed and optimized in-house to screen eight common pathogenic mutations in the CYP21A2 gene. We have also established and utilized a multiplex PCR assay for target enrichment and Next-generation sequencing (NGS) of CYP11B1, CYP17A1, POR, and CYP19A1 genes. Following preliminary amplification of the functional gene CYP21A2, ASPCR based genotyping of eight common mutations - P30L, I2G, 8BPdel, I172N, E6CLUS (I235N, V236E, M238K) V281L, Q318X, and R356W was carried out. These results were further validated using Sanger and Next-generation sequencing. Once optimized to be specific and sensitive, the advantage of ASPCR in CYP21A2 genotyping extends to provide genetic screening for both adult and paediatric subjects and carrier testing at a low cost and less time. Furthermore, multiplex PCR coupled NGS has shown to be cost-effective and robust for parallel multigene sequencing in CAH.

Treatment of congenital adrenal hyperplasia in children aged 0-3 years: a retrospective multicenter analysis of salt supplementation, glucocorticoid and mineralocorticoid medication, growth and blood pressure

Objectives

International guidelines recommend additional salt supplementation during infancy in classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. The influence of corticoid medication and growth has not been assessed.

Aim

To investigate the current use of salt supplementation, fludrocortisone (FC) and hydrocortisone (HC) dosage as well as weight, height, BMI and blood pressure (BP) in CAH children aged 0-3 years.

Methods

Retrospective multicentre analysis using data from the I-CAH registry. Salt-treated (ST) and non-salt-treated (NST) children were compared regarding FC and HC dosage, weight, height and BP at 0, 3, 6, 9, 12, 18, 24, 30, and 36 months.

Results

We analysed 2483 visits of 331 patients born after year 2000 in 13 countries (male, n = 145) with 203 ST patients (61%). NST children had significantly higher FC dosages at 1.5-4.5 months and higher HC dosages until 1.5 months of age. No differences in weight, length and BP between subgroups were observed. Children of the whole cohort showed increased BMI-SDS during the study period and about half of the reported BP readings were >P95.

Conclusion

In children treated with additional salt supplementation, FC and HC dosages are lower during the first months of life but without differences in weight, length and BP until 3 years of age compared to NST children. All children showed an increase in BMI-SDS and a high rate of BP readings >P95 until 3 years, indicating the start of weight gain and negative effects on blood pressure already in very early life.

Molecular Diagnosis of Steroid 21-Hydroxylase Deficiency: A Practical Approach

Adrenal insufficiency in paediatric patients is mostly due to congenital adrenal hyperplasia (CAH), a severe monogenic disease caused by steroid 21-hydroxylase deficiency (21-OHD, encoded by the CYP21A2 gene) in 95% of cases. CYP21A2 genotyping requires careful analyses that guaranty gene-specific PCR, accurate definition of pseudogene-gene chimeras, gene duplications and allele dropout avoidance. A small panel of well-established disease-causing alterations enables a high diagnostic yield in confirming/discarding the disorder not only in symptomatic patients but also in those asymptomatic with borderline/positive results of 17-hydroxyprogesterone. Unfortunately, the complexity of this locus makes it today reluctant to high throughput techniques of massive sequencing. The strong relationship existing between the molecular alterations and the degree of enzymatic deficiency has allowed genetic studies to demonstrate its usefulness in predicting/classifying the clinical form of the disease. Other aspects of interest regarding molecular studies include its independence of physiological variations and analytical interferences, its usefulness in the diagnosis of simple virilizing forms in males and its inherent contribution to the genetic counseling, an aspect of great importance taking into account the high carrier frequency of CAH in the general population. Genetic testing of CYP21A2 constitutes an irreplaceable tool to detect severe alleles not just in family members of classical forms but also in mild late-onset forms of the disease and couples. It is also helpful in areas such as assisted reproduction and preimplantation diagnosis. Molecular diagnosis of 21-OHD under expert knowledge definitely contributes to a better management of the disease in every step of the clinical course.

Genotypic spectrum of 21-hydroxylase deficiency in an endogamous population

BACKGROUND

Congenital adrenal hyperplasia (CAH) due to autosomal recessive 21-hydroxylase deficiency (21-OHD) is caused by defects in the CYP21 (CYP21A2) gene. Several mutations have been identified in the CYP21 (CYP21A2) gene of patients with 21-OHD. We aimed at determining the frequency of these mutations among a group of Egyptian patients and studying the genotype-phenotype correlation.

METHODS

Forty-seven patients with CAH due to 21-OHD from 42 different families diagnosed by clinical and hormonal evaluation and classified accordingly into salt wasting (SW) and simple virilizing (SV) phenotypes were enrolled. Their ages ranged between 1.78 and 18.99 years. Molecular analysis of the CYP21 (CYP21A2) gene was performed for the detection of eleven common mutations: P30L, I2 splice (I2 G), Del 8 bp E3 (G110del8nt), I172N, cluster E6 (I236N, V237E, M239K), V281L, L307 frameshift (F306 + T), Q318X, R356W, P453S, R483P by polymerase chain reaction (PCR) and reverse hybridization.

RESULTS

Disease-causing mutations were identified in 47 patients, 55.31% of them were compound heterozygous. The most frequent mutations were I2 splice (25.43%), followed by cluster E6 (16.66%) and P30L (15.78%). Two point mutations (P453S, R483P) were not identified in any patient. In the SW patients, genotypes were more compatible with their phenotypes.

CONCLUSION

Molecular characterization should be considered along with clinical and biochemical diagnosis of CAH since it could confirm the diagnosis, outline the treatment strategy and morbidity, and ensure proper genetic counseling.

Current and Novel Treatment Strategies in Children with Congenital Adrenal Hyperplasia

BACKGROUND

The standard treatment for congenital adrenal hyperplasia (CAH) in children is still hydrocortisone. Improved strategies for timing of the dose during the day and the dose per square meter body surface area used in children of different ages and developmental phases have improved the situation and outcome for the patients. Neonatal screening enables an earlier diagnosis and initiation of treatment, prevents from adrenal crisis, and improves growth and development also for children with the less severe forms of CAH.

SUMMARY

This review describes the current treatment strategies for children with CAH and discusses some potential treatment options that have been developed with the primary aim to decrease the adrenal androgen production. Novel modified release glucocorticoid therapies are also discussed.

KEY MESSAGES

The long-term effects of the new adjunct therapies are unknown, and some are not suitable for use in children and adolescents. The effects of the new therapies on bone mineral density, gonadal functions, and long-term cognitive development are yet to be assessed. It is not known what levels of adrenal androgens are optimal for normal growth, puberty, and bone health. The basis of using glucocorticoids and mineralocorticoids in the treatment of CAH remains, and in some individuals, it may be beneficial to add therapies to reduce the androgen load during certain life stages.

Characterization of the Interrenal Gland and Sexual Traits Development in cyp17a2-Deficient Zebrafish

Unlike the Cytochrome P450, family 17, subfamily A, member 1 (Cyp17a1), which possesses both 17α-hydroxylase and 17,20-lyase activities involved in the steroidogenic pathway that produces androgens and estrogens, Cytochrome P450, family 17, subfamily A, polypeptide 2 (Cyp17a2) possesses only 17α-hydroxylase activity and is known essential for the synthesis of cortisol. Besides with expressed in testes and ovaries, where the cyp17a1 is mainly expressed, cyp17a2 is also expressed in the interrenal gland in fish. Until now, the roles of cyp17a2 in fish, especially in sexual traits development and hypothalamic-pituitary-interrenal (HPI) axis, are poorly studied. To investigate the roles of Cyp17a2 in teleosts, the cyp17a2-null zebrafish was generated and analyzed by us. The significantly decreased cortisol concentration was observed both in the cyp17a2-deficient males and females at adult stage. The interrenal gland enlargement, increased pituitary proopiomelanocortin a (pomca) expression, decreased locomotion activity and response to light-stimulated stress were observed in cyp17a2-deficient fish. Intriguingly, the cyp17a2-deficient males were fertile and with normal breeding tubercles on the pectoral fin, but females were infertile, deficient in genital papilla and with decreased gonadosomatic index (GSI). The increased progesterone (P4), 17α,20β-dihydroxy-4-pregnen-3-one (DHP) and 11-ketotestosterone (11-KT) in the cyp17a2-deficient males and females were observed. The increased concentration of testosterone (T) and estradiol (E2) was observed in cyp17a2-/- females and cyp17a2-/- males, respectively. By examining the ovaries development of cyp17a2-deficient fish at 3 months postfertilization (mpf), we observed that the oocytes were over-activated. Taken together, our findings demonstrate that Cyp17a2 is indispensable for production and physiology of cortisol, and cyp17a2-deficiency resulted in diminished cortisol but accumulated P4 and DHP, which may result in the over-activated oocytes in cyp17a2-deficient females.

Detection of Small CYP11B1 Deletions and One Founder Chimeric CYP11B2/CYP11B1 Gene in 11β-Hydroxylase Deficiency

OBJECTIVE

11β-Hydroxylase deficiency (11β-OHD) caused by mutations in the CYP11B1 gene is the second most common form of congenital adrenal hyperplasia. Both point mutations and genomic rearrangements of CYP11B1 are important causes of 11β-OHD. However, the high degree of sequence identity between CYP11B1 and its homologous gene CYP11B2, presents unique challenges for molecular diagnosis of suspected 11β-OHD. The aim of this study was to detect the point mutation, indel, small deletion of CYP11B1 and chimeric CYP11B2/CYP11B1 gene in a one-tube test, improving the genetic diagnosis of 11β-OHD.

METHODS

Optimized custom-designed target sequencing strategy was performed in three patients with suspected 11β-OHD, in which both the coverage depth of paired-end reads and the breakpoint information of split reads from sequencing data were analysed in order to detect genomic rearrangements covering CYP11B1. Long-range PCR was peformed to validate the speculated CYP11B1 rearrangements with the breakpoint-specifc primers.

RESULTS

Using the optimized target sequencing approach, we detected two intragenic/intergenic deletions of CYP11B1 and one chimeric CYP11B2/CYP11B1 gene from three suspected patients with 11β-OHD besides three pathogenic heterozygous point mutation/indels. Furthermore, we mapped the precise breakpoint of this chimeric CYP11B2/CYP11B1 gene located on chr8:143994517 (hg19) and confirmed it as a founder rearrangement event in the Chinese population.

CONCLUSIONS

Our optimized target sequencing approach improved the genetic diagnosis of 11β-OHD.

Mineralocorticoid Deficiency as an Early Presenting Symptom of Allgrove Syndrome With Novel Mutation: A Case Report

Allgrove syndrome or Triple-A syndrome is a triad of achalasia, alacrimia, and adrenal insufficiency. It is a rare disease that’s only described in the literature with no known incidence rate. Atypical presentation of some cases is rarely seen, especially with monotonous symptoms. We are describing an early age of presentation with dual symptoms of Allgrove Syndrome than the triplet with novel homozygous variant at c.885G>A in the AAAS gene.

Allele-specific PCR and Next-generation sequencing based genetic screening for Congenital Adrenal Hyperplasia in India

Genetic screening of Congenital Adrenal Hyperplasia (CAH) is known to be challenging due to the complexities in CYP21A2 genotyping and has not been the first-tier diagnostic tool in routine clinical practice. Also, with the advent of massive parallel sequencing technology, there is a need for investigating its utility in screening extended panel of genes implicated in CAH. In this study, we have established and utilized an Allele-Specific Polymerase Chain Reaction (ASPCR) based approach for screening eight common mutations in CYP21A2 gene followed by targeted Next Generation Sequencing (NGS) of CYP21A2, CYP11B1, CYP17A1, POR, and CYP19A1 genes in 72 clinically diagnosed CAH subjects from India. Through these investigations, 88.7% of the subjects with 21 hydroxylase deficiency were positive for eight CYP21A2 mutations with ASPCR. The targeted NGS assay was sensitive to pick up all the mutations identified by ASPCR. Utilizing NGS in subjects negative for ASPCR, five study subjects were homozygous positive for other CYP21A2 variants: one with a novel c.1274G>T, three with c.1451G>C and one with c.143A>G variant. One subject was compound heterozygous for c.955C>T and c.1042G>A variants identified using ASPCR and NGS. One subject suspected for a Simple Virilizing (SV) 21 hydroxylase deficiency was positive for a CYP19A1:c.1142A>T variant. CYP11B1 variants (c.1201-1G>A, c.1200+1del, c.412C>T, c.1024C>T, c.1012dup, c.623G>A) were identified in all six subjects suspected for 11 beta-hydroxylase deficiency. The overall mutation positivity was 97.2%. Our results suggest that ASPCR followed by targeted NGS is a cost-effective and comprehensive strategy for screening common CYP21A2 mutations and the CAH panel of genes in a clinical setting.

Clinical applications of genetic analysis and liquid chromatography tandem-mass spectrometry in rare types of congenital adrenal hyperplasia

BACKGROUND

Our study aims to summarize the clinical characteristics of rare types of congenital adrenal hyperplasia (CAH) other than 21-hydroxylase deficiency (21-OHD), and to explore the clinical applications of genetic analysis and liquid chromatography tandem-mass spectrometry (LC-MS/MS) in rare CAH.

METHODS

We retrospectively analysed the clinical data of 5 rare cases of CAH admitted to our hospital and summarized their clinical manifestations, auxiliary examinations, diagnosis and mutational spectrum.

RESULTS

After gene sequencing, complex heterozygous variants were detected in all patients (2 cases were lipoid congenital adrenal hyperplasia (LCAH), 11β-hydroxylase deficiency (11β-OHD), 3β-hydroxysteroid dehydrogenase deficiency (3β-HSD deficiency) and P450 oxidoreductase deficiency (PORD) each accounted for 1 case), which were consistent with their clinical manifestations. Among them, 4 novel variants were detected, including c.650 + 2 T > A of the StAR gene, c.1145 T > C (p. L382P) of the CYP11B1 gene, c.1622C > T (p. A541V) and c.1804C > T (p. Q602 *) of the POR gene. The LC-MS/MS results for steroid hormones in patients were also consistent with their genetic variants: 2 patients with LCAH showed a decrease in all steroid hormones; 11β-OHD patient showed a significant increase in 11-deoxycortisol and 11-deoxycorticosterone; patient with 3β-HSD deficiency showed a significant increase in DHEA; and PORD patient was mainly characterized by elevated 17OHP, progesterone and impaired synthesis of androgen levels.

CONCLUSIONS

The clinical manifestations and classification of CAH are complicated, and there are cases of missed diagnosis or misdiagnosis. It's necessary to combine the analysis of clinical manifestations and auxiliary examinations for diagnosis; if necessary, LC-MS/MS analysis of steroid hormones or gene sequencing is recommended for confirming diagnosis and typing.

Establishing a molecular genetic diagnosis in children with Differences of Sex Development - a clinical approach

Background Despite distinct underlying aetiologies, the clinical phenotypes and hormonal profiles of children with various differences of sex development (DSD) are often similar, which presents challenges to ascertaining an accurate diagnosis on clinical grounds alone. Associated features and important clinical outcomes can, however, vary significantly in different DSD, thus establishing an accurate molecular diagnosis may have important implications for decision-making and management planning in a given individual. Summary The wider availability of next generation sequencing techniques in recent years has led to recommendations for earlier integration of genetic testing in the diagnostic pathway of children with DSD. This review provides a practical overview of the clinical applications, advantages and limitations of the more commonly available diagnostic genetic tests and outlines a suggested approach to testing. The potential clinical implications of a confirmed genetic diagnosis on subsequent management pathways for individuals with DSD, as well as challenges that remain to be addressed are also outlined. Key messages Despite significant improvements in our understanding of the complex genetic pathways that underlie DSD, an accurate diagnosis still eludes many affected individuals. Establishing a molecular diagnosis provides aetiological certainty, enabling improved information for families and individualised clinical management, including monitoring or prophylactic intervention where higher longer-term health risks exist. A stepwise approach to genomic testing is recommended to afford highest diagnostic yield from available resources. Looking forward, collaborative multicentre prospective studies will be required to assess the true impact of a genetic diagnosis on improving clinical care pathways and health, wellbeing and patient-reported outcomes for individuals with DSD.

2+0 CYP21A2 deletion carrier — a limitation of the genetic testing and counseling: A case report

BACKGROUND

CYP21A2 gene mutations may all cause reduction or loss of 21-hydroxylase activity, leading to development of congenital adrenal hyperplasia (CAH) with different clinical phenotypes. For families with CAH children, genetic testing of the parents and genetic counseling are recommended to assess the risk of recurrence.

CASE SUMMARY

We report a case of CAH with a high suspicion before delivery. The risk of the child suffering from CAH during the pregnancy had been underestimated due to the deviation of genetic counseling and genetic testing results. Our report confirmed a CYP21A2 homozygous deletion in this case, CYP21A2 heterozygous deletion in the mother, and a rare 2+0 CYP21A2 deletion in the father.

CONCLUSION

It is important to analyze the distribution of CYP21A2 gene in the two alleles of parents of children with CAH.

First insights into the genetics of 21-hydroxylase deficiency in the Roma population

BACKGROUND

21-hydroxylase deficiency (21OHD) is an autosomal recessive disorder with an incidence of 1:10,000-1:20,000 and is the result of various mutations in the CYP21A2 gene. 21OHD has been described in many different populations, but it has not been studied in Roma individuals so far. The aim of the study was to analyse the genotype in Roma patients with 21OHD and the prevalence of the disease in the Roma population of North Macedonia.

METHODS

Molecular analysis of the nine most frequent CYP21A2 mutations in all known Roma patients with CAH in North Macedonia, relatives and healthy individuals of Roma ancestry, using the PCR/ACRS method.

RESULTS

Ten Roma patients with 21OHD were identified, of which nine had the salt-wasting and one had the simple virilizing form. Calculated incidence of 21OHD in the North Macedonian Roma population was 1:3375. Interestingly, 9/10 patients (90%) were homozygous for the In2G splicing mutation (293-13A/C > G). Standard therapy with hydrocortisone and fludrocortisone had been introduced according to the guidelines. In 16 healthy relatives investigated for CYP21A2 mutations, heterozygosity for the In2G mutation was detected in 13/32 (40.6%) alleles. In 100 healthy Roma individuals, none related to the analysed families, no CYP21A2 mutations were detected.

CONCLUSION

The Roma population in North Macedonia had a very high incidence of classic 21OHD. Almost all patients had the severe salt-wasting form and the In2G/In2G genotype.

A novel 9 bp deletion (c.1271_1279delGTGCCCGCG) in exon 10 of CYP21A2 gene causing severe congenital adrenal hyperplasia

BACKGROUND

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder of adrenal steroidogenesis with a broad spectrum of clinical presentations, ranging from the severe classical salt-wasting (SW) and simple-virilizing (SV) form, to the mild nonclassical form. A large variety of CYP21A2 genotypes in correlation with phenotype have been described.

MATERIALS AND METHODS

DNA samples from a 14-day-old male newborn with clinical and laboratory signs of SW CAH and family members were subjected for molecular analysis of the nine most common point CYP21A2 mutations by ACRS/PCR method. Direct DNA sequencing of the whole CYP21A2 gene was performed to detect the second mutant allele in the patient. The in silico predicting analysis and the crystal structure analysis of the mutated CYP21A2 protein have been performed.

RESULTS

Molecular analysis confirmed that the patient was compound heterozygote carrying p.Q318X mutation inherited from the mother and a novel c.1271_1279delGTGCCCGCG (p.G424_R426del) variant in exon 10 inherited from the father. The in silico predicting software tools classified the novel mutation as pathogenic. Crystal structure analysis showed that the three residues affected by the novel in-frame deletion form several hydrogen bonds that could lead to impaired stability and function of the CYP21A2 protein. These findings were concordant with the patient's phenotype. The need of several molecular methods to elucidate the genotype in this patient has also been discussed.

CONCLUSIONS

A novel 9 bp deletion in CYP21A2 gene with predicted pathogenic effect on the enzyme activity was detected in neonatal patient causing severe SW CAH.

Genotype and clinical outcomes in children with congenital adrenal hyperplasia

BACKGROUND

The study aimed to delineate the genotypic features and endocrine / metabolic profiles in patients with 21-hydroxylase deficiency.

METHODS

Subjects were diagnosed with 21-hydroxylase deficiency by direct Sanger sequencing or multiple ligation-dependent probe amplification analysis and followed up in Pusan National University Children's Hospital from July 2008 to April 2019. The genotype, phenotype, and endocrine and metabolic profiles in children and young adults with congenital adrenal hyperplasia were investigated.

RESULTS

Of a total of 33 patients, 16 (48.5%) were males. Median age was 7.4 years (range, 0.1-23.8 years). Thirty (90.9%) had salt-wasting phenotypes. Eleven (33.3%) initially presented with abnormality in a neonatal screening test without other symptoms. Among the 17 girls, seven received genital surgery. Sixty-five alleles from the 33 patients were evaluated. The distribution of CYP21A2 gene mutations revealed an intron 2 splice site (c.293-13A>G or c.293-13C>G) mutation as the most common one (22, 33.8%), followed by c.518T>A (10, 15.4%) and a large deletion / conversion (7, 10.8%), in order. One novel mutation was detected, c.332del(p.G111fs). Among the 27 patients aged >2 years, fifteen (55.6%) were obese / overweight, and ten (37.0%) needed growth hormone therapy due to short stature. Among the seven subjects aged >2 years and having high-risk genotype, five had impaired fasting glucose, three had precocious puberty, and four used growth hormone. A greater proportion of the high current corticosteroid dose group had impaired fasting glucose than in the low-dose group (64.3 vs 23.1%, P = 0.031).

CONCLUSIONS

Early monitoring of endocrine and metabolic complications from childhood might benefit patients with congenital adrenal hyperplasia.

Non-Classical 21-Hydroxylase Deficiency: Analysis of a Mutant Gene in a Uyghur Family and Literature Review

OBJECTIVE

The gene mutation and clinical characteristics of a patient with non-classical 21-hydroxylase deficiency and his family were analyzed.

METHODS

A patient was diagnosed with non-classical 21-hydroxylase deficiency in the Department of Endocrinology of People's Hospital of Xinjiang Uygur Autonomous Region in December 2016. The clinical data and related gene-sequencing results were analyzed. The detected mutations were verified in nine members of the family.

RESULTS

Gene-sequencing results revealed that the proband and the other three members of the family (proband, proband's mother's younger brother and the proband's mother's younger brother's younger daughter, and proband's second elder sister) shared the following mutations: Ile173Asn, Ile237Asn, Val238Glu, Met240Lys, Val282Leu, Leu308Phefs*6, Gln319Ter, Arg357Trp, and Arg484Profs. The Val282Leu mutation was heterozygous in the proband's mother's younger brother's younger daughter, but homozygous in the other three individuals. The father of the proband, the elder brother of the father of the proband, the third younger brother of the father of the proband, and the elder sister of the proband all carried only the Val282Leu mutation.

CONCLUSION

Val282Leu is the gene responsible for non-classical 21-hydroxylase deficiency. Screening for this gene in the offspring of patients with non-classical 21-hydroxylase deficiency may help to identify cases early.

Congenital Adrenal Hyperplasia (CAH) and Gitelman Syndrome (GS): Overlapping Symptoms in an Uncommon Association

Background

Classical salt-wasting (SW) congenital adrenal hyperplasia (CAH) and Gitelman syndrome (GS) are two genetic conditions in which dyselectrolytemia may occur. No association between the two conditions has been previously described. Case Presentation. We present the case of a boy with a neonatal diagnosis of SW-CAH who showed low potassium blood levels from the age of 15 years. This electrolytic alteration was, at first, attributed to an excessive action of mineralocorticoid drugs. Due to persistence of hypokalemia, SLC12A3 whole genome sequencing was performed, showing a heterozygous C to T base pair substitution at position 965 in gene SLC12A3. This mutation is related to Gitelman syndrome with autosomal recessive transmission.

Conclusions

SW-CAH and GS determine opposite values of potassium in the absence of specific therapy, with a natural tendency to compensate each other. The symptom overlap makes diagnosis difficult. Organic causes of hypokalemia in patients undergoing life-saving therapy should not be excluded.