OBJECTIVETo investigate the value of direct sequencing of sex-determining region Y (SRY) gene, as well as peripheral blood karyotype analysis, in the diagnosis of disorders of sex development (DSD) among children and adolescents with ambiguous genitalia.

METHODSThe karyotypes of 20 children and adolescents with ambiguous genitalia were determined by conventional G-banding analysis. PCR amplification was used to detect SRY gene in these patients, and direct sequencing was used to judge whether there was SRY gene mutation.

RESULTSOf the 20 cases, 17 were positive for SRY gene, and 3 were negative for SRY gene. Direct sequencing revealed no SRY gene mutation in the positive cases, however karyotype analysis found 4 special karyotypes in these patients: 46, XY, del(Y) (q12)/45, X; 46, XY, add(Y) (p11); 46, XY, r(9); 46, XY, 9qh+.

CONCLUSIONSSRY gene detection can help determine the type of DSD among children and has the advantage of quick detection. Used together with G-banding analysis, it is helpful for primary diagnosis of DSD among children.