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Background: 5α-reductase type 2 deficiency (5αRD) is an autosomal recessive hereditary disease of the group of 46, XY disorders of sex development (DSD). Objective: To study the growth pattern in Chinese pediatric patients with 5αRD. Subjects: Data were obtained from 141 patients with 5αRD (age: 0–16 years old) who visited eight pediatric endocrine centers from January 2010 to December 2017. Methods: In this retrospective cohort study, height, weight, and other relevant data were collected from the multicenter hospital registration database. Baseline luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T), and dihydrotestosterone (DHT) after human chorionic gonadotropin (HCG) stimulation test were measured by enzyme enhanced chemiluminescence assay. Bone age (BA) was assessed using the Greulich-Pyle (G-P) atlas. Growth curve was constructed based on λ-median-coefficient of variation method (LMS). Results: The height standard deviation scores (HtSDS) and weight standard deviation scores (WtSDS) in 5αRD children were in the normal range as compared to normal boys. Significantly higher HtSDS was observed in patients with 5αRD who were <1 year old (t = 3.658, 2.103, P = 0.002, 0.048, respectively), and higher WtSDS in those <6 months old (t = 2.756, P = 0.012). Then HtSDS and WtSDS decreased gradually and fluctuated near the median of the same age until 13 years. WtSDS in 5αRD children from northern China were significantly higher than those from the south (Z = -2.670, P = 0.008). The variation tendency of HtSDS in Chinese 5αRDs was consistent with the trend of stimulating T. HtSDS and stimulating T in the external masculinization score (EMS) <7 group were slightly higher than those in EMS ≥ 7 group without significant difference. Additionally, the ratio of BA over chronological age (BA/CA) was significantly <1 in children with 5αRD. Conclusion: Children with 5αRD had a special growth pattern that was affected by high levels of T, while DHT played a very small role in it. Their growth accelerated at age <1 year, followed by slowing growth and fluctuating height near normal median boys' height. The BA was delayed in 5αRD children. Androgen treatment, which may be considered anyway for male 5αRD patients with a micropenis, may also be beneficial for growth. [ABSTRACT FROM AUTHOR]

In this study, we investigated the genetics, clinical features, and therapeutic approach of 14 patients with 5α-reductase deficiency in China. Genotyping analysis was performed by direct sequencing of PCR products of the steroid 5α-reductase type 2 gene (SRD5A2). The 5α-reductase activities of three novel mutations were investigated by mutagenesis and an in vitro transfection assay. Most patients presented with a microphallus, variable degrees of hypospadias, and cryptorchidism. Eight of 14 patients (57.1%) were initially reared as females and changed their social gender from female to male after puberty. Nine mutations were identified in the 14 patients. p.G203S, p.Q6X, and p.R227Q were the most prevalent mutations. Three mutations (p.K35N, p.H162P, and p.Y136X) have not been reported previously. The nonsense mutation p.Y136X abolished enzymatic activity, whereas p.K35N and p.H162P retained partial enzymatic activity. Topical administration of dihydrotestosterone during infancy or early childhood combined with hypospadia repair surgery had good therapeutic results. In conclusion, we expand the mutation profile of SRD5A2 in the Chinese population. A rational clinical approach to this disorder requires early and accurate diagnosis, especially genetic diagnosis., Competing Interests: None

Background: The 5α-reductase type 2 (5α-RD2) deficiency caused by mutations in the steroid 5α-reductase 2 ( SRD5A2 ) gene results in variable degrees of undervirilisation in patients with 46,XY disorders of sex development. This study aims to profile the regional distribution and phenotype-genotype characteristics of SRD5A2 in a large Chinese 5α-RD2 deficiency cohort through multi-centre analysis., Methods: 190 subjects diagnosed with 5α-RD2 deficiency were consecutively enrolled from eight medical centres in China. Their clinical manifestations and genetic variants were analysed., Results: Hypospadias (isolated or combined with microphallus and/or cryptorchidism) was fairly common in the enrolled subjects (66.32%). 42 variants, including 13 novel variants, were identified in SRD5A2 . Homozygous and compound heterozygous mutations presented in 38.42% and 61.58% of subjects, respectively, and predominated in exons 1, 4 and 5. The most prevalent variant was c.680G > A (52.37%), followed by c.16C > T, (10.79%), c.607G > A, (9.21%) and c.737G > A, (8.95%). However, their distributions were different: c.680G > A was more common in South China than in North China (62.62% vs 39.16%, p < 0.001), whereas the regional prevalence of c.16C > T was reversed (6.07% vs 16.87%, p = 0.001). Furthermore, c.680G > A prevailed in cases with normal meatus (68.75%) or distal hypospadias (66.28%), compared with those with proximal hypospadias (35.54%, p < 0.001). However, cases with proximal hypospadias showed a higher frequency of c.16C > T (20.48%) than those with normal meatus (3.13%) or distal hypospadias (3.49%, p < 0.001)., Conclusions: This study profiled variable phenotypic presentation and wide mutational spectrum of SRD5A2, revealing its distinctive regional distribution in Chinese patients and further shaping the founder effect and genotype-phenotype correlation of SRD5A2 ., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)