Evaluation and characterization of a high-resolution melting analysis kit for rapid carrier-screening test of spinal muscular atrophy.

ABSTRACT

Spinal muscular atrophy (SMA) is a common autosomal recessive disorder in humans, caused by the homozygous absence of the survival motor neuron gene 1 (SMN1). SMN2, a copy gene, influences the severity of SMA. Several assays have been described for molecular diagnosis or carrier screening of SMA. A newly developed tool based on a high-resolution melting analysis (HRMA) that enables high-throughput screening without sophisticated protocols but low costs reveals itself to be powerful. We evaluate the performance of an HRMA-based kit for a carrier-screening test of SMA that was designed to detect the substitution of a single nucleotide in SMN1 exon 7. Carriers were identified in 453 participants by quantifying the SMN1 gene and compared with denaturing high-performance liquid chromatography (DHPLC) assay. An HRMA-based kit had a higher sensitivity (100%) for carrier testing than the DHPLC assay (93%), with the added advantage that some homozygous sequence alterations could be identified. The HRMA kit is a new, fast, and highly reliable quantitative test for the SMA molecular carrier test.