A Humanized and Viable Animal Model for Congenital Adrenal Hyperplasia-CYP21A2-R484Q Mutant Mouse.

Congenital Adrenal Hyperplasia (CAH) is an autosomal recessive disorder impairing cortisol synthesis due to reduced enzymatic activity. This leads to persistent adrenocortical overstimulation and the accumulation of precursors before the blocked enzymatic step. The predominant form of CAH arises from mutations in CYP21A2, causing 21-hydroxylase deficiency (21-OHD). Despite emerging treatment options for CAH, it is not always possible to physiologically replace cortisol levels and counteract hyperandrogenism. Moreover, there is a notable absence of an effective in vivo model for pre-clinical testing. In this work, we developed an animal model for CAH with the clinically relevant point mutation p.R484Q in the previously humanized CYP21A2 mouse strain. Mutant mice showed hyperplastic adrenals and exhibited reduced levels of corticosterone and 11-deoxycorticosterone and an increase in progesterone. Female mutants presented with higher aldosterone concentrations, but blood pressure remained similar between wildtype and mutant mice in both sexes. Male mutant mice have normal fertility with a typical testicular appearance, whereas female mutants are infertile, exhibit an abnormal ovarian structure, and remain in a consistent diestrus phase. Conclusively, we show that the animal model has the potential to contribute to testing new treatment options and to prevent comorbidities that result from hormone-related derangements and treatment-related side effects in CAH patients.

Fertility and sexual activity in patients with Triple A syndrome.

Objective: Triple A syndrome, caused by autosomal recessively inherited mutations in the AAAS gene is characterized by alacrima, achalasia, adrenal insufficiency, and neurological impairment. To the best of our knowledge, no patients of both sexes have been reported to have offspring. Our aim was to assess the causes of infertility in male patients with this multisystemic syndrome, and to present a female patient that spontaneously conceived a child. Design: Cross-sectional study. Methods: Six males aged 19-48 years were included. Gonadotropins, testosterone, DHEAS, androstenedione, inhibin B, anti-Mullerian hormone measurements and testicular ultrasound were performed. Results: All six male patients had impaired general health and neurological symptoms including erectile and ejaculatory dysfunction. None of them had an offspring. The only demonstrated cause of infertility in our male patients was erectile and ejaculatory dysfunction which precludes sexual intercourse. Our patients had normal libido but were sexually abstinent. Except for low adrenal androgen levels, the concentrations of all measured hormones as well as testicular ultrasound were normal which may indicate the possibility of spermatogenesis in male patients with triple A syndrome. Little is known about fertility in female patients, but based on our observations spontaneous pregnancies seem to be possible. Conclusion: Our results contribute to still scarce knowledge on fertility in patients with Triple A syndrome and as well represents a foundation for further research on causes of infertility and possible treatment options.

Biallelic NDC1 variants that interfere with ALADIN binding are associated with neuropathy and triple A-like syndrome.

Nuclear pore complexes (NPCs) regulate nucleocytoplasmic transport and are anchored in the nuclear envelope by the transmembrane nucleoporin NDC1. NDC1 is essential for post-mitotic NPC assembly and the recruitment of ALADIN to the nuclear envelope. While no human disorder has been associated to one of the three transmembrane nucleoporins, biallelic variants in AAAS, encoding ALADIN, cause triple A syndrome (Allgrove syndrome). Triple A syndrome, characterized by alacrima, achalasia, and adrenal insufficiency, often includes progressive demyelinating polyneuropathy and other neurological complaints. In this report, diagnostic exome and/or RNA sequencing was performed in seven individuals from four unrelated consanguineous families with AAAS-negative triple A syndrome. Molecular and clinical studies followed to elucidate the pathogenic mechanism. The affected individuals presented with intellectual disability, motor impairment, severe demyelinating with secondary axonal polyneuropathy, alacrima, and achalasia. None of the affected individuals has adrenal insufficiency. All individuals presented with biallelic NDC1 in-frame deletions or missense variants that affect amino acids and protein domains required for ALADIN binding. No other significant variants associated with the phenotypic features were reported. Skin fibroblasts derived from affected individuals show decreased recruitment of ALADIN to the NE and decreased post-mitotic NPC insertion, confirming pathogenicity of the variants. Taken together, our results implicate biallelic NDC1 variants in the pathogenesis of polyneuropathy and a triple A-like disorder without adrenal insufficiency, by interfering with physiological NDC1 functions, including the recruitment of ALADIN to the NPC.