Targeted next-generation sequencing identification of mutations in patients with disorders of sex development

BMC Med Genet. 2016 Mar 15;17:23. doi: 10.1186/s12881-016-0286-2.

Abstract

Background: The identification of causative mutations is important for treatment decisions and genetic counseling of patients with disorders of sex development (DSD). Here, we designed a new assay based on targeted next-generation sequencing (NGS) to diagnose these genetically heterogeneous disorders.

Methods: All coding regions and flanking sequences of 219 genes implicated in DSD were designed to be included on a panel. A total of 45 samples were used for sex chromosome dosage validation by targeted sequencing using the NGS platform. Among these, 21 samples were processed to find the causative mutation.

Results: The sex chromosome dosages of all 45 samples in this assay were concordant with their corresponding karyotyping results. Among the 21 DSD patients, a total of 11 mutations in SRY, NR0B1, AR, CYP17A1, GK, CHD7, and SRD5A2 were identified, including five single nucleotide variants, three InDels, one in-frame duplication, one SRY-positive 46,XX, and one gross duplication with an estimated size of more than 427,038 bp containing NR0B1 and GK. We also identified six novel mutations: c.230_231insA in SRY, c.7389delA in CHD7, c.273C>G in NR0B1, and c.2158G>A, c.1825A>G, and c.2057_2065dupTGTGTGCTG in AR.

Conclusions: Our assay was able to make a genetic diagnosis for eight DSD patients (38.1%), and identified variants of uncertain clinical significance in the other three cases (14.3%). Targeted NGS is therefore a comprehensive and efficient method to diagnose DSD. This work also expands the pathogenic mutation spectrum of DSD.

Keywords: Disorders of sex development; Novel mutation; Targeted next-generation sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asian Continental Ancestry Group / genetics
  • China
  • Disorders of Sex Development / diagnosis
  • Disorders of Sex Development / genetics*
  • Female
  • Genetic Testing
  • High-Throughput Nucleotide Sequencing / methods*
  • Humans
  • Male
  • Mutation*
  • Polymorphism, Single Nucleotide
  • Reproducibility of Results
  • Sequence Alignment
  • Sequence Analysis, DNA / methods
  • Sex Chromosomes / genetics
  • Sexual Development / genetics