ABSTRACT
Objective To explore the clinical feature and gene mutation in steroid 5α-reductase 2 deficiency (SRD5A2). Method The clinical data of SRD5A2 in a child with vulva abnormality as the first manifestation was retrospectively analyzed. Results This was a 29-month-old child, whose social gender was female. The level of her basic luteinizing hormone (LH) was 0.07 mIU/mL, and follicle-stimulating hormone was (FSH) 0.39 mIU/mL. The baseline levels of testosterone (T), dihydrotestosterone (DHT), 17-hydroxyprogesterone (17-OHP) and androstendione (A2) were 0.06 ng/mL, 19.67 pg/mL, 1.20 ng/mL, and 0.07 ng/mL respectively. Those levels were 3.65 ng/mL, 68.25 pg/mL, 51.72 ng/mL, and 14.70 ng/mL respectively after Human chorionic gonadotropin (HCG) stimulation. The levels of her anti-mullerian hormone (AMH) was 22.97 ng/mL, and inhibin B (INH-B) was 274.4 pg/mL. The uterus and ovaries were not detected by Pelvic ultrasound and MRI. The chromosome showed 46, XY. Sex determination (SRY) gene detection showed normal. Androgen receptor (AR) gene detection showed negative. There was pathogenic mutation of 5α-reductase 2 (SRD5A2) gene in peripheral blood of the child and her parents. The penis grows 2 cm after 4 months of treatment with 2.5% DHT gel. Conclusion SRD5A2 is diagnosed mainly based on the increase of T/DHT after HCG stimulation experiment and it can be confirmed by detection of pathogenic SRD5A2 mutation.
ABSTRACT
Monomelic amyotrophy (MA), also known as Hirayama disease, occurs mainly in young men and manifests as weakness and wasting of the muscles of the distal upper limbs. Here, we sought to identify a genetic basis for MA. Given the predominance of MA in males, we focused on candidate neurological disease genes located on the X chromosome, selecting two X-linked candidate genes, androgen receptor (AR) and ubiquitin-like modifier activating enzyme 1 (UBA1). Screening for genetic variants using patients' genomic DNA revealed three known genetic variants in the coding region of the AR gene: one nonsynonymous single-nucleotide polymorphism (SNP; rs78686797) encoding Leu57Gln, and two variants of polymorphic trinucleotide repeat segments that encode polyglutamine (CAG repeat; rs5902610) and polyglycine (GGC repeat; rs3138869) tracts. Notably, the Leu57Gln polymorphism was found in two patients with MA from 24 MA patients, whereas no variants were found in 142 healthy male controls. However, the numbers of CAG and GGC repeats in the AR gene were within the normal range. These data suggest that the Leu57Gln polymorphism encoded by the X-linked AR gene may contribute to the development of MA.