Thioredoxin Reductase 2 (TXNRD2) Variant As A Cause Of Micropenis, Undescended Testis And Selective Glucocorticoid Deficiency.

INTRODUCTION: Variants in genes that play a role in maintaining cellular redox homeostasis in adrenocortical cells may be associated with glucocorticoid deficiency and it is unclear whether these cases may be associated with a wider phenotype. However, to date, only one case of a genetic variant in TXNRD2, the gene encoding thioredoxin reductase Type 2, in a South Asian kindred with familial glucocorticoid deficiency has been reported. CASE PRESENTATION: The index case was diagnosed with selective glucocorticoid deficiency at 10 years of age. He had a history of a small penis and a right undescended testis which subsequently required an orchidopexy. The parents were of Pakistani origin and first cousins. The boy's gonadal function was normal and autosomal recessive missense homozygous variants p.Val361Met;Val361Met in thioredoxin reductase 2 gene (TXNRD2) were identified in him by WGS. Functional studies were performed using peripheral blood mononuclear cells (PBMCs) from the patient, unaffected parents and four age-matched healthy boys. Compared to the carriers and controls, the case had lower TXNRD2 protein on immunoblotting using anti-TXNRD2 antibody (1.3 fold) 95% CI: 1.8 (1.5-2.1), lower mRNA expression of TXNRD2 on quantitative RT-PCR (1.6 fold) 95% CI: 1.1 (0.7-1.4) and a lower glutathione (GSH):oxidized glutathione (GSSG) ratio (6.7 fold) 95% CI: 2.0 (1.6-2.4). CONCLUSIONS: In addition to confirming the critical role that TXNRD2 serves in maintaining adrenal function, by reporting the findings of atypical genitalia, this case further extends the phenotype.

Salivary androgens in adolescence and their value as a marker of puberty: results from the SCAMP cohort.

Context: Salivary androgens represent non-invasive biomarkers of puberty that may have utility in clinical and population studies. Objective: To understand normal age-related variation in salivary sex steroids and demonstrate their correlation to pubertal development in young adolescents. Design, setting and participants: School-based cohort study of 1495 adolescents at two time points for collecting saliva samples approximately 2 years apart. Outcome measures: The saliva samples were analyzed for five androgens (testosterone, androstenedione (A4), 17-hydroxyprogesterone, 11-ketotestosterone and 11ß-hydroxyandrostenedione) using liquid chromatography-mass spectrometry; in addition, salivary dehydroepiandrosterone (DHEA) and oestradiol (OE2) were analysed by ELISA. The pubertal staging was self-reported using the Pubertal Development Scale (PDS). Results: In 1236 saliva samples from 903 boys aged between 11 and 16 years, salivary androgens except DHEA exhibited an increasing trend with an advancing age (ANOVA, P < 0.001), with salivary testosterone and A4 concentration showing the strongest correlation (r = 0.55, P < 0.001 and r = 0.48, P < 0.001, respectively). In a subgroup analysis of 155 and 63 saliva samples in boys and girls, respectively, morning salivary testosterone concentrations showed the highest correlation with composite PDS scores and voice-breaking category from PDS self-report in boys (r = 0.75, r = 0.67, respectively). In girls, salivary DHEA and OE2 had negligible correlations with age or composite PDS scores. Conclusion: In boys aged 11-16 years, an increase in salivary testosterone and A4 is associated with self-reported pubertal progress and represents valid non-invasive biomarkers of puberty in boys.

The Use of Genetics for Reaching a Diagnosis in XY DSD.

Reaching a firm diagnosis is vital for the long-term management of a patient with a difference or disorder of sex development (DSD). This is especially the case in XY DSD where the diagnostic yield is particularly low. Molecular genetic technology is playing an increasingly important role in the diagnostic process, and it is highly likely that it will be used more often at an earlier stage in the diagnostic process. In many cases of DSD, the clinical utility of molecular genetics is unequivocally clear, but in many other cases there is a need for careful exploration of the benefit of genetic diagnosis through long-term monitoring of these cases. Furthermore, the incorporation of molecular genetics into the diagnostic process requires a careful appreciation of the strengths and weaknesses of the evolving technology, and the interpretation of the results requires a clear understanding of the wide range of conditions that are associated with DSD.