High-throughput screening reveals novel mutations in spinal muscular atrophy patients

Abstract

Background Spinal muscular atrophy (SMA) is an autosomal recessive hereditary disease associated with severe muscle atrophy and weakness in the limbs and trunk. The discovery of genes mutated by SMA is helpful in diagnosis and treatment. Methods 83 whole blood samples were collected from 28 core families of clinically suspected SMA, and multiplex ligation probe amplification (MLPA) was firstly performed. Afterwards, the complete gene sequence of SMN1 gene was detected. Furthermore, 20 SMA patients were selected from the 28 probands, and 5 non SMA children as controls. The Life Technologies SOLiD™ technology with mate-pair chemistry was utilized to conduct the whole exome high-throughput sequencing. Results 22 probands were SMA patients, 3 probands carriers, and 3 probands normal individuals. Moreover, 2 parents from 2 SMA families were with 3 SMN1 exon7 copies. 6 SMN1 single nucleotide variants (SNVs) were identified in the 83 samples, and c.[84C>T], c.[271C>T], c.[-39A>G] and g.[70240639G>C] were novel. Compared with control group, 9102 mutation were selected out in SMA patients. SPTA1 mutation c.[-41_-40insCTCT], FUT5 SNV c.[1001A>G], and MCCC2 SNV c.[-117A>G] were the 3 most frequent mutations in SMA group (95%, 85% and 75%, respectively). Conclusions We identified some mutations in both SMN1 and other genes, and c.[271C>T], c.[-41_-40insCTCT], c.[1001A>G] and c.[-117A>G] might be associated with the onset of SMA.