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Objectives: To examine the changes in diagnostic practices and clinical management of patients with 5α-reductase type 2 (SRD5A2) or 17β-hydroxysteroid dehydrogenase type 3 (HSD17B3) deficiency since molecular diagnoses became available. Methods: Clinical, laboratory, and therapeutic data were retrieved from the medical records of 52 patients with a molecular diagnosis of SRD5A2 (n = 31) or HSD17B3 (n = 21) deficiency. Temporal trends regarding age at assessment and initial sex assignment over 1994–2020 were qualitatively analyzed. Age at molecular diagnosis was compared between two subgroups of patients according to their year of birth. Results: Fifty-eight percent (n = 30) patients were diagnosed during the perinatal period, 33% (n = 17) during infancy, and 9% (n = 5) during adolescence or adulthood. Over the studied period, the patients’ age at initial assessment and diagnosis frankly decreased. The median (range) age at diagnostic confirmation was 10.5 (0–53.2) years for patients born before 2007 and 0.4 (0–9.3) years for those born in 2007 or later (P = 0.029). Genetic testing identified 27 different variants for the SRD5A2 gene (30% novel, n = 8) and 18 for the HSD17B3 gene (44% novel, n = 8). Before 2002, most patients were initially assigned as females (95%, n = 19), but this proportion dropped for those born later (44%, n = 14; P < 0.001). The influence of initial genital appearance on these decisions seemingly decreased in the most recent years. Therapeutic interventions differed according to the sex of rearing. Ten percent (n = 2) patients requested female-to-male reassignment during adulthood. Conclusion: This study showed, over the past two decades, a clear trend toward earlier diagnosis and assignment of affected newborns as males.

Ting Gui,1,&ast; Fengxia Yao,2,&ast; Xinzhuang Yang,2 Xi Wang,3 Min Nie,3 Xueyan Wu,3 Qinjie Tian1 1Department of Obstetrics and Gynecology, National Clinical Research Center for Obstetric and Gynecologic Diseases, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China; 2Department of Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China; 3Department of Endocrinology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Qinjie Tian, Department of obstetrics and gynecology, Peking Union Medical College Hospital, No. 1, Shuaifuyuan Road, Dongcheng District, Beijing, 100730, People’s Republic of China, Tel +86 010-69158335, Email tqj_tianqinjie@163.comObjective: The 5α-reductase type 2 deficiency is mainly caused by mutations in the SRD5A2 gene. Our study aims to investigate the SRD5A2 gene mutations and their corresponding manifestations.Methods: Four unrelated Chinese patients with 46, XY ambiguous genitalia were studied. Molecular genetic alterations and clinical presentations were analyzed.Results: Five variants in the SRD5A2 gene were identified, all highly conserved in vertebrate orthologs. The p.P251A was a novel variant, predicted to “Affect protein function” and to be “probably damaging”. Combining patients’ gene mutations with their external genitalia and male sexual characteristics, we found that three variants, p.Q6X, p.N193S, and p.H90Y, were associated with severe undervirilization of external genitalia, and the other two, p.G203S and p.P251A, probably retained part of the enzyme activity.Conclusion: Mutation analysis of SRD5A2 gene is crucial for differential diagnosis in patients with 5α-reductase type 2 deficiency. Patients’ variable manifestations depend on the mutation type and residual enzyme activity. The novel variant p.P251A enlarges the spectrum of SRD5A2 mutations.Keywords: 5α-reductase type 2 deficiency, SRD5A2 gene mutation, androgen receptor insensitivity, disorders of sex development, differential diagnosis

The 5α-reductase type 2 enzyme catalyzes the conversion of testosterone into dihydrotestosterone, playing a crucial role in male development. This enzyme is encoded by the SRD5A2 gene, which maps to chromosome 2 (2p23), consists of 5 exons and 4 introns, and encodes a 254 amino acid protein. Disruptions in this gene are the molecular etiology of a subgroup of differences of sex development (DSD) in 46,XY patients. Affected individuals present a large range of external genitalia undervirilization, ranging from almost typically female external genitalia to predominantly typically male external genitalia with minimal undervirilization, including isolated micropenis. This is an updated review of the implication of the SRD5A2 gene in 5α-reductase type 2 enzyme deficiency. For that, we identified 451 cases from 48 countries of this particular 46,XY DSD from the literature with reported variants in the SRD5A2 gene. Herein, we present the SRD5A2 mutational profile, the SRD5A2 polymorphisms, and the functional studies related to SRD5A2 variants to detail the molecular etiology of this condition. [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.

Introduction: The conversion of testosterone into dihydrotestosterone is catalyzed by the 5α-reductase type 2 enzyme which plays a crucial role in the external genitalia virilization. It is encoded by the SRD5A2 gene. Allelic variants in this gene cause a 46,XY DSD with no genotype–phenotype relationship. It was firstly reported in the early 70s from isolated clusters. Since then, several cases have been reported. Putting together, it will expand the knowledge on the molecular bases of androgen milieu. Methods: We searched for SRD5A2 allelic variants (AV) in the literature (PubMed, Embase, MEDLINE) and websites (ensembl, HGMD, ClinVar). Only cases with AV in both alleles, either in homozygous or compound heterozygous were included. The included cases were analyzed according to ethnicity, exon, domain, aminoacid (aa) conservation, age at diagnosis, sex assignment, gender reassignment, external genitalia virilization and functional studies. External genitalia virilization was scored using Sinnecker scale. Conservation analysis was carried out using the CONSURF platform. For categorical variables, we used X2 test and Cramer's V. Continuous variables were analyzed by t test or ANOVA. Concordance was estimated by Kappa. Results: We identified 434 cases of 5ARD2 deficiencies from 44 countries. Most came from Turkey (23%), China (17%), Italy (9%), and Brazil (7%). Sixty-nine percent were assigned as female. There were 70% of homozygous allelic variants and 30% compound heterozygous. Most were missense variants (76%). However, small indels (11%), splicing (5%) and large deletions (4%) were all reported. They were distributed along with all exons with exon 1 (33%) and exon 4 (25%) predominance. Allelic variants in the exon 4 (NADPH-binding domain) resulted in lower virilization (p< 0.0001). The codons 55, 65, 196, 235 and 246 are hotspots making up 25% of all allelic variants. Most of them (76%) were located at conserved aa. However, allelic variants at non-conserved aa were more frequently indels (28% vs 6%; p< 0.01). The overall rate of gender change from female to male ranged from 16% to 70%. The lowest rate of gender change from female to male occurred in Turkey and the highest in Brazil. External genitalia virilization was similar between those who changed and those who kept their assigned gender. The gender change rate was significantly different across the countries (V=0.44; p< 0.001) even with similar virilization scores. Conclusion: 5ARD2 deficiency has a worldwide distribution. Allelic variants at the NADPH-ligand region cause lower virilization. Genitalia virilization influenced sex assignment but not gender change which was influenced by cultural aspects across the countries. Molecular diagnosis influenced on sex assignment, favoring male sex assignment in newborns with 5α-reductase type 2 deficiency. [ABSTRACT FROM AUTHOR]

Background5α-reductase type 2 deficiency (5αRD) is an autosomal recessive hereditary disease of the group of 46, XY disorders of sex development (DSD).ObjectiveTo study the growth pattern in Chinese pediatric patients with 5αRD.SubjectsData were obtained from 141 patients with 5αRD (age: 0–16 years old) who visited eight pediatric endocrine centers from January 2010 to December 2017.MethodsIn 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).ResultsThe 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

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]

The article focuses on the study of Male assignment in 5a-reductase type 2 deficiency with female external genitalia. Topics discussed include Posterior reversible encephalopathy syndrome (PRES) can occur in diverse situations and is characterized by seizures, impairment of consciousness, headaches, visual abnormalities, nausea, and vomiting; and most cases are caused by systemic hypertension but there are other etiological conditions and entities, including immunosuppressant drug use.

The 5α-reductase type 2 (5α-RD2) deficiency is one of the most common etiology of 46, XY disorders of sex development and is caused by pathogenic variants in SRD5A2. Massively parallel sequencing contributes to identification of numerous novel SRD5A2 variants, in vitro functional study could help to determine their pathogenicity. In this study, we aim to present the functional study of fifteen SRD5A2 variants found in Chinese patients and explore the genotype–phenotype association. We collected the clinical manifestation and genotype of 38 patients with 5α-RD2 deficiency who visited our center between 2009 and 2021. The pathogenicity of seven missense SRD5A2 variants, were predicted by in-silico tools. Furthermore, fifteen SRD5A2 variants without reported functional assay were studied in vitro to analyze the role of these variants in enzymatic activity. Twenty-four SRD5A2 rare variants were identified in 38 patients with 5α-RD2 deficiency. Fifteen variants without reported functional assay decreased the conversation of testosterone (T) to dihydrotestosterone(DHT) and caused the almost complete loss of enzyme activity (<8 %) in our in-vitro functional study. Thirty-eight patients with three different external genital phenotypes (complete female, clitoromegaly and hypospadias) were found to have same variants. Patients with different testicular position (scrotum/clitoris and cryptorchidism) were found to have same variants. Our study showed 15 SRD5A2 variants caused complete loss of 5α-RD2 enzyme activity by functional study. Patients with different clinical phenotypes can have the same genotypes and no obvious genotype–phenotype association exist in our series patients. • This study presented in vitro functional study of fifteen SRD5A2 variants and explored the genotype–phenotype association in our patients with 5α-RD2 deficiency. • Our study showed fifteen SRD5A2 variants caused complete loss of 5α-RD2 enzyme activity (<8 %) by in vitro functional study. • Patients with different clinical phenotypes can have the same genotypes and we found no obvious genotype–phenotype association in our series patients. [ABSTRACT FROM AUTHOR]

The SRD5A2 gene that encodes SRD5A2 enzyme is placed on chromosome 2p23. The gene includes 5 exons that are translated into a 254-amino acid protein. To evaluate SRD5A2 gene that encodes SRD5A2 enzyme is placed on chromosome 2p23 accompany with biotinidase deficiency in case with ambiguous external genitalia. We investigated a case with ambiguous external genitalia for cytogenetic and gene mutation analysis. Gene mutation analysis and cytogenetic analysis were performed according to a standard DNA sequencing method and the present international standard nomenclature (ISCN), respectively. A Novel p.Arg179Ser (c.537 G>T) heterozygotes mutation on exon 3 of SRD5A2 gene accompany with biotinidase deficiency was detected. The chromosomal analysis result is 46, XY. This is the first case with biotinidase deficiency and novel R179S p.Arg179Ser (c.537 G>T) mutation of the SRD5A2 gene, which cause 5-alpha reductase deficiency. [ABSTRACT FROM AUTHOR]

The 5α-reductase type 2 deficiency is a rare autosomal recessive 46,XY disorder of sex development caused by the mutated 5α-reductase type 2 (SRD5A2) gene. In this disease, defective conversion of testosterone to dihydrotestosterone leads to variable presentations of male ambiguous genitalia during fetal development. The most crucial clinical decision for the affected individual is proper gender assignment; therefore, a prompt and correct diagnosis is important. In this present study, we report a normal male karyotype manifesting microphallus, bifid scrotum/labia majora with bilateral palpable gonads, and a blind-ended pseudovagina. The mutation analysis of the SRD5A2 gene revealed one novel C to T transition changing glutamine to a stop codon at codon 71 (p.Q71X) in exon 1 and one known G to A transition changing arginine to glutamine at codon 227 (p.R227Q) in exon 4. The p.Q71X mutation presumably results in a truncated protein, while the p.R227Q mutation is conceived to impair enzyme function and has been reported in patients of East Asian descent. This report demonstrates the essential role of hormonal and molecular studies for genetic counseling and gender assignment in males with pseudovaginal disorder of sex development, and our report helps identify a novel SRD5A2 gene mutation in the Taiwanese population.

Objectives: To examine the changes in diagnostic practices and clinical management of patients with 5α-reductase type 2 (SRD5A2) or 17β-hydroxysteroid dehydrogenase type 3 (HSD17B3) deficiency since molecular diagnoses became available., Methods: Clinical, laboratory, and therapeutic data were retrieved from the medical records of 52 patients with a molecular diagnosis of SRD5A2 (n = 31) or HSD17B3 (n = 21) deficiency. Temporal trends regarding age at assessment and initial sex assignment over 1994-2020 were qualitatively analyzed. Age at molecular diagnosis was compared between two subgroups of patients according to their year of birth., Results: Fifty-eight percent (n = 30) patients were diagnosed during the perinatal period, 33% (n = 17) during infancy, and 9% (n = 5) during adolescence or adulthood. Over the studied period, the patients' age at initial assessment and diagnosis frankly decreased. The median (range) age at diagnostic confirmation was 10.5 (0-53.2) years for patients born before 2007 and 0.4 (0-9.3) years for those born in 2007 or later (P = 0.029). Genetic testing identified 27 different variants for the SRD5A2 gene (30% novel, n = 8) and 18 for the HSD17B3 gene (44% novel, n = 8). Before 2002, most patients were initially assigned as females (95%, n = 19), but this proportion dropped for those born later (44%, n = 14; P < 0.001). The influence of initial genital appearance on these decisions seemingly decreased in the most recent years. Therapeutic interventions differed according to the sex of rearing. Ten percent (n = 2) patients requested female-to-male reassignment during adulthood., Conclusion: This study showed, over the past two decades, a clear trend toward earlier diagnosis and assignment of affected newborns as males.

Background Testicular morphology and immunohistochemical studies have never been reported in genetically documented adult patients with 5 alpha-reductase type 2 deficiency (5α-R2 deficiency). Case presentation We describe the testicular histopathology of a 17-year-old XY subject with 5α-R2 deficiency caused by the recurrent homozygous Gly115Asp loss of function mutation of the SRD5A2 gene. We also performed an immunohistochemical analysis in order to further study the relationship between seminiferous tubules structure, Sertoli cell differentiation and androgenic signaling impairment in this case. We thus evaluated the testicular expression of theanti-Müllerian hormone (AMH), androgen receptor (AR) and 3β-hydroxysteroid dehydrogenase (3ßHSD). Histological analysis revealed a heterogeneous aspect with a majority (92%) of seminiferous tubules (ST) presenting a mature aspect but containing only Sertoli cells and devoid of germ cells and spermatogenesis. Focal areas of immature ST (8%) were also found. Testicular AR and 3βHSD expression were detected in adult male control, 5α-R2 deficiency and CAIS subjects. However, AMH expression was heterogeneous (detectable only in few AR negative prepubertal ST, but otherwise repressed) in the 5α-R2 deficiency, conversely to normal adult testis in which AMH was uniformly repressed and to an adult CAIS testis in which AMH was uniformly and strongly expressed. Conclusion Intratesticular testosterone can repress AMH by itself, independently of its metabolism into dihydrotestosterone. We also compare our results to the few post pubertal cases of 5α-R2 deficiency with available histological testicular description, reported in the literature. We will discuss these histological findings, in the more general context of evaluating the fertility potential of these patients if they were raised as males and were azoospermic. [ABSTRACT FROM AUTHOR]

Objective: To investigate the functional change of SRD5A2 gene mutations identified in patients with 5α-reductase type 2 deficiency. Patients and Methods: Three unrelated subjects born with ambiguous genitalia were included. All patients were initially reared as girls, but they gradually exhibited variable degrees of virilization at puberty without breast development, followed by a change of gender role. Sequencing analysis of the SRD5A2 gene was performed and enzymatic activities of 5α-reductase type 2 were assessed. Results: Three compound heterozygous mutations in the SRD5A2 gene were identified: patient 1 with p.G203S/ c.655delT, patient 2 with p.Q6X/p.G203S, and patient 3 with p.G203S/c.755_756insT. Heterozygosity for the p.V89L polymorphism was also found in patients 2 and 3. The c.655delT mutation led to a complete loss of the enzymatic activity, whereas mutants p.G203S and c.755_756insT resulted in a reduction of the enzymatic activities by 60 and 90%, respectively. Conclusion: Two frameshift heterozygous mutations, c.655delT and c.755_756insT, led to a dramatic reduction in 5α-reductase activity, and the latter had not been reported previously. In addition, the heterozygous mutation (p.G203) identified in the 3 patients presumably suggests a founder effect in the Chinese population and may explain the similarity in phenotype among the patients. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Disorders of androgen production can occur in all steps of testosterone biosynthesis and secretion carried out by the foetal Leydig cells as well as in the conversion of testosterone into dihydrotestosterone (DHT). The differentiation of Leydig cells from mesenchymal cells is the first walk for testosterone production. In 46,XY disorders of sex development (DSDs) due to Leydig cell hypoplasia, there is a failure in intrauterine and postnatal virilisation due to the paucity of interstitial Leydig cells to secrete testosterone. Enzymatic defects which impair the normal synthesis of testosterone from cholesterol and the conversion of testosterone to its active metabolite DHT are other causes of DSD due to impaired androgen production. Mutations in the genes that codify the enzymes acting in the steps from cholesterol to DHT have been identified in affected patients. Patients with 46,XY DSD secondary to defects in androgen production show a variable phenotype, strongly depending of the specific mutated gene. Often, these conditions are detected at birth due to the ambiguity of external genitalia but, in several patients, the extremely undervirilised genitalia postpone the diagnosis until late childhood or even adulthood. These patients should receive long-term care provided by multidisciplinary teams with experience in this clinical management. [Copyright &y& Elsevier]

Aims: The aim of this study was to perform a 5α-reductase type 2 gene (SRD5A2) analysis in 6 Korean patients with external genitalia ranging from predominantly female to male in whom 5α-reductase type 2 deficiency was suspected. Patients: Six patients from five unrelated families participated, and all of their parents were non-consanguineous. Three patients presented with ambiguous genitalia at birth, and 2 were referred owing to delayed puberty. The other patient was presented incidentally during an operation for inguinal hernia. Basal and post-human chorionic gonadotropin-stimulated serum testosterone and dihydrotestosterone levels were determined, but neither the levels nor ratio yielded enough information for differential diagnosis. Confirmative diagnosis was achieved by SRD5A2 gene analysis. Results: Four different pathologic mutations were identified. All have already been reported, and are located in exon 1 (p.Q6X), exon 4 (p.G203S and c.655delT), and exon 5 (p.R246Q). p.R246Q was the most frequently identified mutation in our study, and c.655delT has been detected only in Korean patients to date. Conclusion: The molecular analysis is the most reliable method for a correct diagnosis of 5α-reductase type 2 deficiency. Identification of mutations also enables genetic counseling for families at risk. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

5α-reductase (5α-R) deficiency is an important cause of ambiguious genitalia in genetic males; however therapeutic experience in literature is limited. In this report authors describe a child with 46 XY Disorder of Sexual Differentiation (DSD), due to 5α-reductase deficiency, who was managed with Dihydrotestosterone (DHT) gel. [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.)

Objective: To describe two unrelated Thai patients with suspected 5α-reductase type 2 deficiency and perform mutation analysis of the SRD5A2 gene. Design: Case report. Setting: A pediatric endocrinology clinic at a university hospital. Patient(s): Two unrelated patients with 46,XY karyotype, born with ambiguous genitalia, were studied. One was reared as a boy and the other was reared as a girl. Intervention(s): The entire coding regions of the SRD5A2 gene were assessed by polymerase chain reaction (PCR) and sequencing analysis. Main Outcome Measure(s): Molecular characterization of the SRD5A2 gene. Result(s): Four different pathogenic mutations (three missense and one nonsense) were identified. These were located at exon 1 (p.Q6X and p.L20P), exon 3 (p.G183S), and exon 4 (p.G203S). The T>C transition (c.59T>C) resulting in a leucine-to-proline substitution at codon 20 (p.L20P) has not been previously described and was not detected in 100 unaffected, ethnic-matched control chromosomes. In addition, p.G183S, previously identified only among patients from mixed African–European ancestry and in the Dominican Republic, was also detected in a Thai patient. Conclusion(s): This study demonstrates that the SRD5A2 gene is responsible for 5α-reductase type 2 deficiency across different populations and emphasizes the important role of genetic testing for the definite diagnosis and genetic counseling before gender assignment or any surgical intervention. [Copyright &y& Elsevier]