OBJECTIVETo investigate the splice variants of the calpain 3 gene existing in human skeletal muscle tissue and white blood cells, and to explore the feasibility of gene diagnosis using CAPN3 mRNA extracted from peripheral leukocytes.

METHODSTotal RNA was extracted from peripheral blood and skeletal muscle tissue in healthy individuals. CAPN3 cDNAs were determined by reverse transcriptase polymerase chain reaction and DNA sequencing. CAPN3 cDNAs from peripheral leukocytes were compared with sequences obtained from skeletal muscle tissue.

RESULTSRT-PCR and DNA sequencing showed that the CAPN3 cDNAs comprised 24 exons in human skeletal muscle tissue, while the number of exons was 23 in white blood cells. Exon 15 was spliced out in human white blood cells.

CONCLUSIONSplice variants exist in human skeletal muscle tissue and white blood cells. Gene diagnosis may omit the mutations of exon 15 using mRNA extracted from peripheral leukocytes. These findings suggest that mutation analysis of the CAPN3 cDNA should use skeletal muscle tissue as materials instead of peripheral blood.