OBJECTIVETo screen for carriers of SMN1 gene mutation, which underlies spinal muscular atrophy (SMA), in 4931 pregnant women from Liuzhou region of Guangxi, and to determine the carrier rate.

METHODSCombined denaturing high-performance liquid chromatography (DHPLC) and multiple PCR techniques were used to detect the copy number of SMN1 gene. The carrier frequency was calculated. The spouse of the carrier was also screened, and prenatal diagnosis was provided to the couples who were both positive.

RESULTSAmong the 4931 pregnant women, 61 were found to harbor only one copy of the SMN1 gene, which yielded a carrier rate of 1.2%. Subsequent testing has identified 1 fetus carrying homozygous deletions of the SMN1 gene.

CONCLUSIONThe carrier rate of SMA mutation in Liuzhou region is slightly lower than that of other regions of southern China. DHPLC can effectively screen the carriers of SMA mutation and provide a basis for genetic counseling and prenatal diagnosis.