摘要目的 比较CAPN3基因在外周血白细胞和骨骼肌组织中的剪切变异,探讨用外周血白细胞CAPN3 mRNA进行基因诊断的可行性.方法 抽提正常人外周血和骨骼肌组织中总RNA,通过逆转录-聚合酶链反应和DNA测序确定CAPN3基因的cDNA序列,比较外周血白细胞和骨骼肌组织中CAPN3cDNA序列.结果 由骨骼肌组织抽提的RNA进行逆转录合成cDNA为CAPN3基因全长cDNA,包含全部24个外显子;而由外周血白细胞抽提的RNA进行逆转录合成cDNA为CAPN3基因非全长cDNA,包含23个外显子,缺失了第15外显子.结论 人的CAPN3基因在骨骼肌和外周血自细胞中存在着不同的剪切方式,若用外周血抽提RNA进行CAPN3基因的编码序列分析时会漏检第15外显子的突变.这提示从cDNA水平分析CAPN3基因突变时应采用患者肌肉组织,而非外周血白细胞.

abstractsObjective To 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. Methods Total 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. Results RT-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. Conclusion Splice 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.