High aldosterone and cortisol levels in salt wasting congenital adrenal hyperplasia: a clinical conundrum

The spectrum of CYP21A2 gene mutations in patients with classic salt wasting form of 2l-hydroxylase deficiency in a Chinese cohort

Background

21‐Hydroxylase deficiency (21‐OHD) caused by the CYP21A2 gene mutations is the most common form of congenital adrenal hyperplasia. It is an autosomal recessive disorder that results in defective synthesis of cortisol and aldosterone. The incidences of various CYP21A2 gene mutations and the genotype–phenotype correlations vary among different populations.

Materials and Methods

The clinical and molecular data of 22 patients were analyzed in this study. All patients were recruited from the neonatal intensive care unit. Locus‐specific polymerase chain reaction and Sanger sequencing were applied to identify gene micro‐conversions, and multiplex ligation‐dependent probe amplification was used to detect large fragment deletions/conversions. Then, the genotypes were categorized in to Null, A, B, C, and D groups to analyze the relationships between genotypes and phenotypes.

Results

All 22 patients were classified into classic salt wasting form of 21‐OHD. Molecular defects were detected in 44 alleles (100%). Micro‐conversion mutation IVS2‐13A/C>G (70.5%) is most common in our cohort, followed by large gene deletions and conversions (22.7%). The other mutations present were p.R357 W (4.5%) and E6 Cluster (2.3%). Genotypes of 22 patients (100%) were consistent with the predictive phenotypes.

Conclusion

In this study, we identified the mutation spectrum of CYP21A2 gene in Chinese patients, especially the younger age cohort in pediatrics. Micro‐conversions were the most popular mutations. Moreover, the genotypes and phenotypes were well correlated in this cohort of salt wasting 21‐OHD recruited from neonatal intensive care unit.

We identified the mutation spectrum of CYP21A2 gene in Chinese patients, especially the younger age cohort admitted in NICU. The genotypes and phenotypes in 21‐OHD were well correlated.

False elevation of serum cortisol in chemiluminescence immunoassay by Siemens Advia Centaur XP system in 21-hydroxylase deficiency: an ‘endocrine laboma’

Liquid chromatography–mass spectrometry, the gold standard method for cortisol measurement, is expensive and not widely available in the developing countries. Chemiluminescent immunoassay, commonly used for cortisol measurement is prone to clinically meaningful inter-assay variability in some analysers. This occurs due to non-specific nature of anticortisol antibodies used in different platforms, having cross reactivity with structurally similar cortisol precursors like 17α-hydroxyprogesterone (17OHP), 11-deoxycortisol and 21-deoxycortisol. In patients with 21-hydroxylase deficiency, where 17OHP and 21-deoxycortisol are significantly elevated, older generation machines like Siemens Advia Centaur XP provide spuriously high cortisol concentration compared with values measured by Roche Cobas e 411 or Siemens Immulite 1000. Diagnosis of potentially life-threatening salt-wasting 21-hydroxylase deficiency may be missed and treatment may be delayed due to such interference. Two children with classic 21-hydroxylase deficiency are being reported here, in whom high cortisol values were observed in Siemens Advia Centaur XP system.

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.

Congenital Adrenal Hyperplasia Presenting as Pulseless Ventricular Tachycardia in a Neonate

Congenital adrenal hyperplasia (CAH) comprises a group of autosomal recessive inherited disorders that arise due to defects in one of the enzymes of steroidogenesis pathway in the adrenal glands. Ninety-five percent of the cases occur due to deficiency in 21-hydroxylase (21-OH). Clinically, CAH due to 21-OH deficiency presents in two distinct forms, classic CAH and non-classic CAH. Females with classical forms present with genial ambiguity while the presentation in males is more subtle with severe electrolyte disturbances being the initial manifestation in many cases. Arrhythmias are a rare manifestation of CAH. We report the case of an 18-day-old male child who presented with pulseless ventricular tachycardia and was later diagnosed with congenital adrenal hyperplasia based on the laboratory findings of elevated 17-hydroxyprogesterone (17-OHP) levels. Our case reveals that fatal arrhythmias such as a pulseless ventricular tachycardia can be the primary manifestation of the adrenal insufficiency of CAH even in the absence of any physical findings and hence clinicians should always maintain a strong suspicion for CAH in any child presenting with unexplained arrhythmia. Furthermore, this case also highlights the need for CAH screening in neonates so that the appropriate hormone replacement can be initiated before the development of life-threatening adrenal crisis.