Phenotypic and biochemical characteristics and molecular basis in 36 Chinese patients with androgen receptor variants

Abstract

BackgroundAndrogen insensitive syndrome (AIS) is a rare genetic disease resulting from androgen receptor (AR) mutations and one of the causes of 46, XY disorder of sexual development (DSD). This study aimed to describe the clinical features and molecular defects of 36 Chinese patients with AR variants and investigate the functional alterations of novel variants in vitro.Material and methodsSubjects with AR variants were identified from 150 Chinese 46, XY DSD patients using targeted next-generation sequencing. In-silico and functional assays were performed to evaluate the transcriptional activity and nuclear localization of novel AR variants.ResultsEight novel and fifteen reported AR variants were identified. 30.6% (11/36) of patients harbored additional variants other than AR. Mutations in the Arg841 residue were found in 7 unrelated patients. Postpubertal serum gonadotropin levels were significantly elevated in patients with complete AIS (CAIS) compared with those in patients with partial AIS (PAIS) (P < 0.05). All the novel variants initially predicted to be uncertain significance by in-silico analyses were reclassified as likely pathogenic for defective AR transcriptional activity in vitro, except p.L295P, which was found in an atypical patient with oligogenic mutations and reclassified as likely benign. c.368_369 ins T was observed to interfere with nuclear translocation.ConclusionsCompared with PAIS patients, postpubertal CAIS patients had higher gonadotropin levels. Arg841 was disclosed as the location of recurrent mutations in Chinese AIS patients. Functional assays are important for reclassifying the novel AR variants and re-examining the diagnosis of AIS in specific patients with oligogenic mutations, instead of in-silico analysis.