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

High clinical utility of long-read sequencing for precise diagnosis of congenital adrenal hyperplasia in 322 probands

BACKGROUND

The molecular genetic diagnosis of congenital adrenal hyperplasia (CAH) is very challenging due to the high homology between the CYP21A2 gene and its pseudogene CYP21A1P.

METHODOLOGY

This study aims to assess the clinical efficacy of targeted long-read sequencing (T-LRS) by comparing it with a control method based on the combined assay (NGS, Multiplex ligation-dependent probe amplification and Sanger sequencing) and to introduce T-LRS as a first-tier diagnostic test for suspected CAH patients to improve the precise diagnosis of CAH.

RESULTS

A large cohort of 562 participants including 322 probands and 240 family members was enrolled for the perspective (96 probands) and prospective study (226 probands). The comparison analysis of T-LRS and control method have been performed. In the perspective study, 96 probands were identified using both the control method and T-LRS. Concordant results were detected in 85.42% (82/96) of probands. T-LRS performed more precise diagnosis in 14.58% (14/96) of probands. Among these, a novel 4141 kb deletion involving CYP21A2 and TNXB was established. A new diagnosis was improved by T-LRS. The duplications were also precisely identified to clarify the misdiagnosis by MLPA. In the prospective study, Variants were identified not only in CYP21A2 but also in HSD3B2 and CYP11B1 in 226 probands. Expand to 322 probands, the actual frequency of duplication haplotype (1.55%) could be calculated due to the accurate genotyping. Moreover, 75.47% of alleles with SNVs/indels, 22.20% of alleles with deletion chimeras.

CONCLUSION

T-LRS has higher resolution and reduced cost than control method with accurate diagnosis. The clinical utility of L-LRS could help to provide precision therapy to CAH patients, advance the life-long management of this complex disease and promote our understanding of CAH.

Congenital lipoid adrenal hyperplasia with Graves' disease: A case report

BACKGROUND

Congenital adrenal hyperplasia (CAH), which is caused by a mutation of the steroidogenic acute regulatory (StAR) gene. Affected patients are usually characterized by adrenal insufficiency in the first year of life, salt loss, glucocorticoid and mineralocorticoid deficiency, and female external genitalia, regardless of chromosomal karyotype. Patients with non-classical lipoid CAH usually develop glucocorticoid deficiency and mild mineralocorticoid deficiency at 2-4 years of age.

CASE SUMMARY

Herein, We report the case of a woman with non-classic lipoid CAH combined with Graves' disease. Her chromosome karyotype was 46, XX, and high-throughput sequencing revealed two missense variants in the StAR gene: c.229C > T (p.Q77X) and c.814C > T (p.R272C), which were inherited from both parents (non-close relatives). The patient was treated for Graves' disease in a timely manner and the dosage of glucocorticoid was adjusted during the treatment of Graves' disease.

CONCLUSION

This is the first case of non-classic lipoid CAH combined with Graves' disease reported in the Chinese population. In addition to conventional glucocorticoid replacement therapy, timely adjustments were made to the dosages of thyroid hormone and glucocorticoid to avoid adrenal crisis as a consequence of the increased demand and accelerated metabolism of glucocorticoids when the patient was diagnosed with Graves' disease.

Approach of Heterogeneous Spectrum Involving 3beta-Hydroxysteroid Dehydrogenase 2 Deficiency

We aim to review data on 3beta-hydroxysteroid dehydrogenase type II (3βHSD2) deficiency. We identified 30 studies within the last decade on PubMed: 1 longitudinal study (N = 14), 2 cross-sectional studies, 1 retrospective study (N = 16), and 26 case reports (total: 98 individuals). Regarding geographic area: Algeria (N = 14), Turkey (N = 31), China (2 case reports), Morocco (2 sisters), Anatolia (6 cases), and Italy (N = 1). Patients’ age varied from first days of life to puberty; the oldest was of 34 y. Majority forms displayed were salt-wasting (SW); some associated disorders of sexual development (DSD) were attendant also—mostly 46,XY males and mild virilisation in some 46,XX females. SW pushed forward an early diagnosis due to severity of SW crisis. The clinical spectrum goes to: premature puberty (80%); 9 with testicular adrenal rest tumours (TARTs); one female with ovarian adrenal rest tumours (OARTs), and some cases with adrenal hyperplasia; cardio-metabolic complications, including iatrogenic Cushing’ syndrome. More incidental (unusual) associations include: 1 subject with Barter syndrome, 1 Addison’s disease, 2 subjects of Klinefelter syndrome (47,XXY/46,XX, respective 47,XXY). Neonatal screening for 21OHD was the scenario of detection in some cases; 17OHP might be elevated due to peripheral production (pitfall for misdiagnosis of 21OHD). An ACTH stimulation test was used in 2 studies. Liquid chromatography tandem–mass spectrometry unequivocally sustains the diagnostic by expressing high baseline 17OH-pregnenolone to cortisol ratio as well as 11-oxyandrogen levels. HSD3B2 gene sequencing was provided in 26 articles; around 20 mutations were described as “novel pathogenic mutation” (frameshift, missense or nonsense); many subjects had a consanguineous background. The current COVID-19 pandemic showed that CAH-associated chronic adrenal insufficiency is at higher risk. Non-adherence to hormonal replacement contributed to TARTs growth, thus making them surgery candidates. To our knowledge, this is the largest study on published cases strictly concerning 3βHSD2 deficiency according to our methodology. Adequate case management underlines the recent shift from evidence-based medicine to individualized (patient-oriented) medicine, this approach being particularly applicable in this exceptional and challenging disorder.