RESUMO
OBJECTIVE@#To carry out prenatal diagnosis for families with high risk for spinal muscular atrophy (SMA) by using multiplex ligation-dependent probe amplification (MLPA).@*METHODS@#Twenty-one families were enrolled. MLPA was used to detect copy numbers of SMN1 and SMN2 genes. Maternal contamination was excluded by using a short tandem repeat method.@*RESULTS@#For 23 fetuses from the 21 families, 14 were identified as carriers, 1 as SMA patient, and 8 as normal. By linkage analysis of parental samples, three individuals were determined as silent (2+0) carriers.@*CONCLUSION@#MLPA can determine the carrier status of SMA. The identification of three silent (2+0) carriers among the 44 parental samples indicated a risk for such families, for which genetic counseling and reproduction guidance should be provided.