目的　筛查中国汉族内脏异位综合征患儿DNAI1和DNAH5基因编码区突变情况。方法　临床招募确诊内 脏异位综合征患儿及健康体检儿童，提取外周血DNA行全外显子组测序，检测DNAI1及DNAH5基因编码区核苷酸变异； Sanger测序验证外显子测序发现的突变位点；以生物信息学软件Mutationtaster、SIFT、PolyPhen-2分析位点变异对蛋白功 能的影响。结果　81例内脏异位综合征患儿及89例健康儿童的外显子测序结果可用于后续分析。在81例内脏异位综合 征患儿中发现存在3个DNAI1及3个DNAH5基因的编码区突变位点， 4例（4.94%）患儿携带DNAI1基因突变， 2例（2.50%） 患儿携带DNAH5基因突变；突变位点在89例健康儿童中均未发现。生物信息学分析提示上述突变位点可能破坏蛋白质 功能。结论　中国汉族内脏异位综合征患儿DNAI1和DNAH5基因突变发生率分别为4.94%和2.50%，DNAI1和DNAH5 基因突变可能与中国汉族儿童内脏异位发生相关。

Objective　To screen the mutations in coding region of DNAI1 and DNAH5 genes in heterotaxy syndrome in Chinese Han children. Methods　Children diagnosed with heterotaxy syndrome and healthy children were recruited clinically. Peripheral blood DNA was extracted for whole exon sequencing, and nucleotide variations in the coding region of DNAI1 and DNAH5 genes were detected. Sanger sequencing was performed to verify the mutation sites found by exon sequencing. The effect of site variation on protein function was analyzed by bioinformatics software Mutationtaster, SIFT and PolyPhen-2. Results　Exon sequencing results of 81 children with heterotaxy syndrome and 89 healthy children can be used for follow-up analysis. Three coding region mutation sites in each of DNAI1 and DNAH5 gene were found in 81 children with heterotaxy syndrome. Four (4.94%) children carried DNAI1 gene mutation, and 2 (2.50%) carried DNAH5 gene mutation. The mutation site was not found in 89 healthy children. Bioinformatics analysis suggests that the above mutation sites may destroy protein function. Conclusions The mutation rates of DNAI1 and DNAH5 gene in Chinese Han children with heterotaxy syndrome were 4.94% and 2.50%, respectively. DNAI1 and DNAH5 gene mutations may be associated with heterotaxy syndrome in Chinese Han children.