[Studies on the molecular diagnosis and prenatal diagnosis of the spinal muscular atrophy carriers by multiplex ligation-dependent probe].

OBJECTIVE: To study the application of the multiplex ligation-dependent probe amplification (MLPA) method in genetic and prenatal diagnosis for spinal muscular atrophy (SMA). METHODS: Four patients, 16 parents and 4 fetuses from 8 SMA pedigrees were included. MLPA was performed for molecular analysis, and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for the mutation detection of the 4 patients. RESULTS: For all the four patients, the same homozygous deletion of the exons 7 and 8 of the survival motor neuron 1 (SMN1) gene, was detected by PCR-RFLP and MLPA. All fourteen parents from the 8 pedigrees were carriers of the SMN1 gene heterozygous deletion, except the mothers in pedigrees 1 and 4 in whom the mutations were different. CONCLUSION: MLPA is a simple and efficient quantitative method for copy number analysis of the SMN genes. It can be used for the genetic diagnosis and prenatal diagnosis of the SMA patients and carriers.