Prevalence, clinical characteristics and long-term outcomes of classical 11 β-hydroxylase deficiency (11BOHD) in Turkish population and novel mutations in CYP11B1 gene

Landscape of congenital adrenal hyperplasia cases in adult endocrinology clinics of Türkiye-a nation-wide multicentre study

BACKGROUND AND AIMS

Congenital adrenal hyperplasia (CAH) is a group of disorders that affect the production of steroids in the adrenal gland and are inherited in an autosomal recessive pattern. The clinical and biochemical manifestations of the disorder are diverse, ranging from varying degrees of anomalies of the external genitalia to life-threatening adrenal insufficiency. This multicenter study aimed to determine the demographics, biochemical, clinical, and genetic characteristics besides the current status of adult patients with CAH nationwide.

METHODS

The medical records of 223 patients with all forms of CAH were evaluated in the study, which included 19 adult endocrinology clinics. A form inquiring about demographical, etiological, and genetic (where available) data of all forms of CAH patients was filled out and returned by the centers.

RESULTS

Among 223 cases 181 (81.16%) patients had 21-hydroxylase deficiency (21OHD), 27 (12.10%) had 11-beta-hydroxylase deficiency (110HD), 13 (5.82%) had 17-hydroxylase deficiency (17OHD) and 2 (0.89%) had 3-beta-hydroxysteroid-dehydrogenase deficiency. 21OHD was the most prevalent CAH form in our national series. There were 102 (56.4%) classical and 79 (43.6%) non-classical 210HD cases in our cohort. The age of the patients was 24.9 ± 6.1 (minimum-maximum: 17-44) for classical CAH patients and 30.2 ± 11.2 (minimum-maximum: 17-67). More patients in the nonclassical CAH group were married and had children. Reconstructive genital surgery was performed in 54 (78.3%) of classical CAH females and 42 (77.8%) of them had no children. Thirty-two (50.8%) NCAH cases had homogenous and 31 (49.2%) had heterogeneous CYP21A2 gene mutations. V281L pathological variation was the most prevalent mutation, it was detected in 35 (55.6%) of 21OHD NCAH patients.

CONCLUSION

Our findings are compatible with the current literature except for the higher frequency of 110HD and 17OHD, which may be attributed to unidentified genetic causes. A new classification for CAH cases rather than classical and non-classical may be helpful as the disease exhibits a large clinical and biochemical continuum. Affected cases should be informed of the possible complications they may face. The study concludes that a better understanding of the clinical characteristics of patients with CAH can improve the management of the disorder in daily practice.

Identification and functional characterization of compound heterozygous CYP11B1 gene mutations

PURPOSE

11β-Hydroxylase deficiency (11β-OHD) is the second leading cause of congenital adrenal hyperplasia (CAH), a rare autosomal recessive disease caused by mutations in the CYP11B1 gene. We previously reported the case of a male Chinese patient with typical 11β-OHD symptoms. Sanger sequencing revealed that the patient carried a splice-site mutation, c.595+1G>A in the CYP11B1 gene. His mother and sister harbored the heterozygous mutation, c.595+1G>A. Paradoxically, Sanger sequencing did not detect any abnormality in the CYP11B1 gene of his father and brother. Therefore, in this study, we aimed to further explore the exact genetic etiology of 11β-OHD in this pedigree and analyze the functional consequence of the c.595+1G>A mutation.

METHODS

Gemomic DNA was extracted from the peripheral blood leukocytes of the family members and normal control individuals, followed by quantitative real-time polymerase chain reaction (qPCR) to detect the copy number of the target CYP11B1 gene fragment. Mutation analysis was also performed via whole-exome sequencing (WES) followed by Sanger sequencing validation. In vitro minigene assay was also performed to investigate the impact of the c.595+1G>A mutation on pre-mRNA splicing.

RESULTS

qPCR results suggested a heterozygous deletion encompassing position c.595+1 along with flanking exonic and intronic sequences in the CYP11B1 gene of the patient and his father. WES followed by Sanger sequencing verified that the patient carried compound heterozygous mutations in the CYP11B1 gene, including a novel 2840-bp deletion (c.395+661_c.1121+180del) and c.595+1G>A, while his father carried the heterozygous c.395+661_c.1121+180del mutation. No other novel CYP11B1 mutations were found in the rest of the family members. Furthermore, minigene assay revealed that the c.595+1G>A mutation resulted in a 70-bp deletion of exon 3 in the mRNA, and this altered the reading frame at amino acid 176 and created a premature stop codon at amino acid 197.

CONCLUSION

We identified a novel 2840-bp-sized large deletion and confirmed that the c.595+1G>A mutation disrupts normal pre-mRNA splicing. Either mutation could significantly alter the reading frame and abolish CYP11B1 enzyme activity. Therefore, our findings widen the mutation spectrum of CYP11B1 and provide an accurate diagnosis of 11β-OHD at a molecular genetic level.

Rare forms of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders due to pathogenic variants in genes encoding enzymes and cofactors involved in adrenal steroidogenesis. Although 21-hydroxylase, 11β-hydroxylase, 3β-hydroxysteroid dehydrogenase type 2, 17α-hydroxylase/17,20-lyase, P450 oxidoreductase, steroidogenic acute regulatory protein, cholesterol side-chain cleavage enzyme deficiencies are considered within the definition of CAH, the term 'CAH' is often used to refer to '21-hydroxylase deficiency (21OHD)' since 21OHD accounts for approximately 95% of CAH in most populations. The prevalence of the rare forms of CAH varies according to ethnicity and geographical location. In most cases, the biochemical fingerprint of impaired steroidogenesis points to the specific subtypes of CAH, and genetic testing is usually required to confirm the diagnosis. Despite there are significant variations in clinical characteristics and management, most data about the rare CAH forms are extrapolated from 21OHD. This review article aims to collate the currently available data about the diagnosis and the management of rare forms of CAH.

Clinical, biochemical, and biomolecular aspects of congenital adrenal hyperplasia in a group of Cameroonian children and adolescents

OBJECTIVES

Congenital adrenal hyperplasia (CAH) remains one of the most challenging endocrine disorders to diagnose, manage, and treat, especially in Africa where there is lack of neonatal screening program, and limited access to care. Data on biomolecular anomaly are sparse, therefore type of mutations are unknown, increasing management challenges and genetic counseling. The present study aims to describe clinical, biomolecular aspects of a group of Cameroonian patients.

METHODS

We did an observational retrospective study at the pediatric endocrinology unit of the Mother and Child Centre of the Chantal Biya Foundation in Yaounde from May 2013 to December 2019, including all patients diagnosed with CAH.

RESULTS

We consecutively included 31 patients aged less than 21 years, diagnosed CAH. Median age at diagnosis was 1.71 years (IQR 0.08-2.57 years). Abnormal genitalia was the main complain in 48.4%(n=15). The most prevalent genetic anomaly found in our study population (n=24) was on CYP11, found in 16 patients (66.6%) followed by CYP21A2 mutation found in 8 patients. Homozygous mutation of p.Q356X was found in half of patients with 11 hydroxylase deficiency. This mutation was mostly found in people from semi-Bantu tribes, declared non consanguineous.

CONCLUSIONS

11 hydroxylase deficiency is the most prevalent form of CAH found in this group of Cameroonian children.

Metabolic syndrome and cardiovascular morbidity in patients with congenital adrenal hyperplasia

Since the introduction of glucocorticoid (GC) replacement therapy, congenital adrenal hyperplasia (CAH) is no longer a fatal disease. The development of neonatal screening programs and the amelioration of GC treatment strategies have improved significantly life expectancy in CAH patients. Thanks to these achievements, CAH patients are now in their adulthood, but an increased incidence of cardiovascular risk factors has been reported compared to general population in this stage of life. The aim of CAH treatment is to both prevent adrenal insufficiency and suppress androgen excess; in this delicate balance, under- as well as overtreatment might be equally harmful to long-term cardiovascular health. This work examines the prevalence of metabolic features and cardiovascular events, their correlation with hormone levels and GC replacement regimen in CAH patients and focuses on precocious markers to early detect patients at higher risk and new potential treatment approaches.

[Congenital adrenal hyperplasia due to 11β-hydroxylase deficiency: late diagnosis and gender reassignment in a two-year-old child]

11β-hydroxylase deficiency is a rare autosomal recessive disorder due to impaired steroidogenesis in the adrenal cortex caused by pathogenic mutations in the CYP11B1 gene. The main clinical manifestations are determined by a deficiency of cortisol, ACTH hyperproduction, excessive androgens secretion and the accumulation of 11-deoxycorticosterone, which leads to the development of arterial hypertension. In the diagnostic search, it is important to take into account the ethnicity of the patient, since the frequency of the disease and the prevalence of mutations differ between ethnic groups. The article presents a clinical case of 11β-hydroxylase deficiency as the result of compound heterozygous mutations in the CYP11B1 gene in a patient of Turkic origin. This case shows the clinical manifestations and the development of complications of 11β-hydroxylase deficiency, the stages of differential diagnosis of patients with 21-hydroxylase deficiency.

Clinical and Hormonal Profiles Correlate With Molecular Characteristics in Patients With 11β-Hydroxylase Deficiency

BACKGROUND

Given the rarity of 11β-hydroxylase deficiency (11βOHD), there is a paucity of data about the differences in clinical and biochemical characteristics of classic (C-11βOHD) and nonclassic 11βOHD (NC-11βOHD).

OBJECTIVE

To characterize a multicenter pediatric cohort with 11βOHD.

METHOD

The clinical and biochemical characteristics were retrospectively retrieved. CYP11B1 gene sequencing was performed. Seventeen plasma steroids were quantified by liquid chromatography-mass spectrometry and compared to that of controls.

RESULTS

102 patients (C-11βOHD, n = 92; NC-11βOHD, n = 10) from 76 families (46,XX; n = 53) had biallelic CYP11B1 mutations (novel 9 out of 30). Five 46,XX patients (10%) were raised as males. Nineteen patients (19%) had initially been misdiagnosed with 21-hydroxylase deficiency. Female adult height was 152 cm [-1.85 SD score (SDS)] and male 160.4 cm (-2.56 SDS).None of the NC-11βOHD girls had ambiguous genitalia (C-11βOHD 100%), and none of the NC-11βOHD patients were hypertensive (C-11βOHD 50%). Compared to NC-11βOHD, C-11βOHD patients were diagnosed earlier (1.33 vs 6.9 years; P < 0.0001), had higher bone age-to-chronological age (P = 0.04) and lower adult height (-2.46 vs -1.32 SDS; P = 0.05). The concentrations of 11-oxygenated androgens and 21-deoxycortisol were low in all patients. The baseline ACTH and stimulated cortisol were normal in NC-11βOHD. Baseline cortisol; cortisone; 11-deoxycortisol; 11-deoxycorticosterone and corticosterone concentrations; and 11-deoxycortisol/cortisol, 11-deoxycorticosterone/cortisol, and androstenedione/cortisol ratios were higher in C-11βOHD than NC-11βOHD patients (P < 0.05). The 11-deoxycortisol/cortisol ratio >2.2, <1.5, and <0.1 had 100% specificity to segregate C-11βOHD, NC-11βOHD, and control groups.

CONCLUSION

NC-11βOHD can escape from clinical attention due to relatively mild clinical presentation. However, steroid profiles enable the diagnosis, differential diagnosis, and subtyping of 11βOHD.

Expanding genetic spectrum and discriminatory role of steroid profiling by LC-MS/MS in 11β-hydroxylase deficiency

OBJECTIVE

To report clinical, hormonal and structural effects of CYP11B1 pathogenic variations in Indian patients with 11β-hydroxylase deficiency (11βOHD) and find hormonal criteria that accurately distinguish 11βOHD from 21α-hydroxylase deficiency (21OHD).

DESIGN

Retrospective record review of genetically diagnosed patients with 11βOHD.

PATIENTS AND MEASUREMENTS

Clinical features, hormonal parameters at diagnosis (by immunoassay) and recent follow-up of 13 genetically proven 11βOHD patients managed at our centre were retrospectively reviewed. ACTH-stimulated serum adrenal steroids (measured by LC-MS/MS) of 11βOHD were compared with those of simple virilizing and non-classic 21OHD. Structural analysis of the observed pathogenic variations was performed by computational modelling.

RESULTS

Nine (four females) and four (all females) patients had classic and non-classic disease, respectively. All 11βOHD patients had elevated ACTH-stimulated serum 11-deoxycortisol (26.5-342.7 nmol/L) whereas none had elevated serum 17-hydroxyprogesterone (4.2-21.2 nmol/L); both hormonal parameters distinguished 11βOHD from 21OHD with 100% accuracy. ACTH-stimulated serum cortisol, but not 11-deoxycortisol, clearly distinguished classic (<70 nmol/L) from non-classic (>160 nmol/L) disease. Thirteen (eight novel, two recurrent) pathogenic variants were observed. Only missense mutations were observed among patients with non-classic disease. Computational modelling predicted the possible affection of enzyme structure and function for all the observed missense mutations.

CONCLUSIONS

This first Indian study describes 13 11βOHD patients, including four with the rarer non-classic variant. A total of eight novel pathogenic variants were identified in our study, highlighting regional genetic heterogeneity. Measurement of ACTH-stimulated adrenal steroids by LC-MS/MS will help avoid the misdiagnosis of 11βOHD as 21OHD and has potential to distinguish classic from non-classic 11βOHD.

Clinical and Molecular Analysis of Four Patients With 11β-Hydroxylase Deficiency

Objective: 11β-hydroxylase deficiency (11βOHD) is a rare autosomal recessive disorder caused by mutations in the CYP11B1 gene. It is characterized by virilization, hypertension, and significant final height impairment. In this study, we aim to investigate the clinical and molecular characteristics of four unrelated Chinese patients with 11βOHD disorder. Methods: The clinical information of four 11βOHD patients were carefully reviewed. Genetic analysis was performed using next-generation sequencing (NGS) based panel analysis. NGS coverage depth was analyzed to detect exonic copy-number variants (CNVs) on patient 1. Quantitative PCR (qPCR) was subsequently performed to confirm the CNVs detected from the NGS coverage depth analysis. Results: The mean age of the patients at diagnosis was 4.7 years (range, 2.0-9.3 years). Two genetically female patients (patients 1 and 2) with 11βOHD presented severe virilization of external genitalia and were raised as males. Two genetically male patients (patients 3 and 4) presented precocious puberty. Additionally, patients 1, 3, and 4 presented with hypertension. In patient 4, unilateral adrenal mass was detected and removed at the age of 9 years. Interestingly, the height of patient 4 (174.4 cm, +6.7 SD) wasn't impaired and reached his mid-parental height (173 cm). Three novel variants in the CYP11B1 gene (c.1150_1153del, c.217C>T, and c.400G>C) were identified by NGS. Various bioinformatics tools revealed potential pathogenic effects for the novel variants, and evolutionary-conservation revealed that the novel missense variant affected an amino acid that is highly conserved among species. Furthermore, NGS coverage depth analysis and qPCR identified a novel heterozygous deletion of exons 1-6 in patient 1. Conclusion: Our study expands the spectrum of mutations of the CYP11B1 gene in Chinese population. In addition, We reported the first case of a patient with classical 11βOHD disorder, whose final height wasn't compromised.

46,XX DSD due to Androgen Excess in Monogenic Disorders of Steroidogenesis: Genetic, Biochemical, and Clinical Features

The term 'differences of sex development' (DSD) refers to a group of congenital conditions that are associated with atypical development of chromosomal, gonadal, or anatomical sex. Disorders of steroidogenesis comprise autosomal recessive conditions that affect adrenal and gonadal enzymes and are responsible for some conditions of 46,XX DSD where hyperandrogenism interferes with chromosomal and gonadal sex development. Congenital adrenal hyperplasias (CAHs) are disorders of steroidogenesis that mainly involve the adrenals (21-hydroxylase and 11-hydroxylase deficiencies) and sometimes the gonads (3-beta-hydroxysteroidodehydrogenase and P450-oxidoreductase); in contrast, aromatase deficiency mainly involves the steroidogenetic activity of the gonads. This review describes the main genetic, biochemical, and clinical features that apply to the abovementioned conditions. The activities of the steroidogenetic enzymes are modulated by post-translational modifications and cofactors, particularly electron-donating redox partners. The incidences of the rare forms of CAH vary with ethnicity and geography. The elucidation of the precise roles of these enzymes and cofactors has been significantly facilitated by the identification of the genetic bases of rare disorders of steroidogenesis. Understanding steroidogenesis is important to our comprehension of differences in sexual development and other processes that are related to human reproduction and fertility, particularly those that involve androgen excess as consequence of their impairment.

Testicular Adrenal Rest Tumors: Current Insights on Prevalence, Characteristics, Origin, and Treatment

This review provides the reader with current insights on testicular adrenal rest tumors (TARTs), a complication in male patients with congenital adrenal hyperplasia (CAH). In recent studies, an overall TART prevalence of 40% (range, 14% to 89%) in classic patients with CAH is found. Reported differences are mainly caused by the method of detection and the selected patient population. Biochemically, histologically, and molecularly, TARTs exhibit particular adrenal characteristics and were therefore thought to originate from aberrant adrenal cells. More recently, TARTs have been found to also exhibit testicular characteristics. This has led to the hypothesis of pluripotent cells as the origin of TARTs. High concentrations of ACTH could cause hyperplasia of these pluripotent cells, as TARTs appear to be associated with poor hormonal control with concomitant elevated ACTH. Unfortunately, as yet there are no methods to prevent the development of TARTs, nor are there guidelines to treat patients with TARTs. Intensified glucocorticoid treatment could improve fertility status in some cases, although studies report contradicting results. TARTs can also lead to irreversible testicular damage, and therefore semen cryopreservation could be offered to patients with TARTs. Further research should focus on the etiology and pharmacological treatment to prevent TART development or to treat TARTs and improve the fertility status of patients with TARTs.

A clinical algorithm to diagnose differences of sex development

The diagnosis and management of children born with ambiguous genitalia is challenging for clinicians. Such differences of sex development (DSDs) are congenital conditions in which chromosomal, gonadal, or anatomical sex is atypical. The aetiology of DSDs is very heterogenous and a precise diagnosis is essential for management of genetic, endocrine, surgical, reproductive, and psychosocial issues. In this Review, we outline a step-by-step approach, compiled in a diagnostic algorithm, for the clinical assessment and molecular diagnosis of a patient with ambiguity of the external genitalia on initial presentation. We appraise established and emerging technologies and their effect on diagnosis, and discuss current controversies.

Typical characteristics of children with congenital adrenal hyperplasia due to 11β-hydroxylase deficiency: a single-centre experience and review of the literature

Background 11β-hydroxylase deficiency (11βOHD) is a rare disease representing the second most common cause of congenital adrenal hyperplasia (CAH) (5-8%) with an incidence of about 1:100,000. In contrast to 21-hydroxylase deficiency (21OHD), 11βOHD is not included in neonatal screening programmes. The objective of this study was to demonstrate the typical features of male patients with 11βOHD. Methods Clinical, biochemical and radiological data of patients with 11βOHD were analysed in this retrospective single-centre analysis. Results Six male patients of four unrelated families with 11βOHD were identified (0.1-13.5 years of chronological age [CA] at diagnosis). The predominant symptoms were arterial hypertension, tall stature and precocious pseudopuberty. Bone ages (BAs) were remarkably advanced at diagnosis in four index patients (median difference BA-CA: 5.5 years, range 1.5-9.2 years). Homozygous mutations were identified in exon 7 (c.1179_1180dupGA [p.Asn394Argfs*37]) and exon 8 (c.1398+2T>C) of the CYP11B1 gene leading both to a complete loss of function. The latter mutation has not yet been described in databases. 11βOHD was identified by the measurement of 11-deoxycortisol in a newborn screening card of one patient retrospectively. Testicular adrenal rest tumours (TARTs) were detected in three patients at 3.7 years, 11 years and 14.4 years. Conclusion The diagnosis of CAH due to 11βOHD is delayed and should be suspected in children with arterial hypertension, tall stature and precocious pseudopuberty. Patients may develop TARTs as early as infancy. 11βOHD should be included in newborn screening programmes, at least in newborns of index families, to allow early diagnosis and the start of treatment to reduce morbidity.

MECHANISMS IN ENDOCRINOLOGY: Rare defects in adrenal steroidogenesis

Congenital adrenal hyperplasia (CAH) is a group of genetic disorders of adrenal steroidogenesis that impair cortisol synthesis, with compensatory increases in ACTH leading to hyperplastic adrenals. The term 'CAH' is generally used to mean 'steroid 21-hydroxylase deficiency' (21OHD) as 21OHD accounts for about 95% of CAH in most populations; the incidences of the rare forms of CAH vary with ethnicity and geography. These forms of CAH are easily understood on the basis of the biochemistry of steroidogenesis. Defects in the steroidogenic acute regulatory protein, StAR, disrupt all steroidogenesis and are the second-most common form of CAH in Japan and Korea; very rare defects in the cholesterol side-chain cleavage enzyme, P450scc, are clinically indistinguishable from StAR defects. Defects in 3β-hydroxysteroid dehydrogenase, which also causes disordered sexual development, were once thought to be fairly common, but genetic analyses show that steroid measurements are generally unreliable for this disorder. Defects in 17-hydroxylase/17,20-lyase ablate synthesis of sex steroids and also cause mineralocorticoid hypertension; these are common in Brazil and in China. Isolated 17,20-lyase deficiency can be caused by rare mutations in at least three different proteins. P450 oxidoreductase (POR) is a co-factor used by 21-hydroxylase, 17-hydroxylase/17,20-lyase and aromatase; various POR defects, found in different populations, affect these enzymes differently. 11-Hydroxylase deficiency is the second-most common form of CAH in European populations but the retention of aldosterone synthesis distinguishes it from 21OHD. Aldosterone synthase deficiency is a rare salt-losing disorder. Mild, 'non-classic' defects in all of these factors have been described. Both the severe and non-classic disorders can be treated if recognized.