RESUMEN
<p><b>OBJECTIVE</b>To investigate the presence of Cosmc gene mutation in children with Henoch-Schönlein purpura (HSP) and the association between Cosmc gene mutation and the susceptibility to HSP.</p><p><b>MESULTS</b>Eighty-four children who were diagnosed with HSP between March 2014 and December 2015 were selected as the HSP group. Fifty-eight healthy volunteers matched for age and sex were enrolled as the control group. Fasting venous blood (5 mL) from the two groups was collected in EDTA anticoagulated tubes, followed by the isolation of peripheral blood mononuclear cells (PBMCs) through density gradient centrifugation. Genomic DNA was extracted from PBMCs according to the manufacturer's protocol, and the whole exon region of Cosmc gene was amplified by touch-down polymerase chain reaction (touch-down PCR). The PCR products were identified by 1% agarose gel and sequenced in order to further examine the association between Cosmc gene mutation and the susceptibility to HSP.</p><p><b>RESULTS</b>Sequencing results showed two mutations (c.393T>A and c.72A>G) of Cosmc gene in children with HSP. There were no significant differences in the genotype and allele frequencies at the two loci between the HSP and control groups, and this distribution was not associated with sex.</p><p><b>CONCLUSIONS</b>The mutations c.393T>A and c.72A>G in the exon region of Cosmc gene in children with HSP are not associated with the onset of HSP.</p>