ABSTRACT
Objective@#To identify pathogenic variants in 5 sporadic patients and two Chinese pedigrees affected with 17-hydroxylase deficiency (17-OHD).@*Methods@#Peripheral blood samples were collected with informed consent. Variants of CYP17A1 gene were screened by PCR and Sanger sequencing. Suspected mutations were validated in other members of the pedigrees.@*Results@#Gene sequencing has identified a homozygous c. 985_987delTACinsAA (Y329Kfs) mutation in exon 6 of the CYP17A1 gene in 4 patients and the sister of case 3. Case 1 was found to harbor compound heterozygous mutations c. 1459_1467del9 (p.D487_F489del) and c. 1244-3C>A. The parents and brother of cases 2 and 5 were heterozygous carriers of a c. 985_987delTACinsAA(Y329Kfs) mutation.@*Conclusion@#Mutations of the CYP17A1 gene probably underlie the pathogenesis of 17-OHD, for which c. 985_987delTACinsAA(Y329Kfs) is the most common. The c. 1244-3C>A is a novel mutation. Above results have facilitated genetic counseling for the affected families.