单纯性法洛四联症患者染色体22q11．2微缺失与临床表型分析

Chromosome 22qi 1. 2 microdeletion and phenotype analysis of patients with non-syndromic tetralogy of Fallot

目的探讨单纯性法洛四联症（tetralogyofFallot，TOF）患儿染色体22qli．2微缺失发生率及其临床表型。方法应用多重连接探针扩增技术（multiplexligation—dependentprobeamplification，MLPA）对68例（男38例、女30例）0～11岁单纯性TOF患儿进行22q11．2微缺失分析，并利用荧光原位杂交（fluorescenceinsituhybridization，FISH）对结果进行验证。运用SPSS11．5软件Fisher确切概率检验进行数据统计分析。结果在68例单纯性TOF患儿中，7例（10．3％）被检出具有22q11．2微缺失，其中4例为肺动脉狭窄型TOF，3例为肺动脉瓣闭锁型TOF。肺动脉瓣闭锁型TOF患儿22q11．2微缺失发生率（3／9，33．3％）明显高于肺动脉狭窄型TOF患儿（4／59，6．80％）（P〈O．05）。结论染色体22q11．2微缺失是单纯性TOF发生的常见遗传学病因。相较于其它类型的TOF，该缺失更容易导致肺动脉瓣闭锁型TOF。临床医生应加强对此类患儿的遗传筛查及咨询。

Objective To investigate the frequency and clinical phenotypes of 22q11.2 mierodeletion in patients with non-syndromic tetralogy of Fallot （TOF）. Methods Six-eight non-syndromic TOF patients （38 males and 30 females, aged 0-11 years） were selected and evaluated by history, physical examination and review of medical records. After informed consent was obtained, peripheral blood was drawn for genomic DNA extraction. Chromosome 22q11.2 microdeletion was screened by multiplex ligation-dependent probe amplification （MLPA）. Suspected cases were confirmed with fluorescence in situ hybridization （FISH）. Data was analyzed with SPSS 11.5 software. Phenotype-genotype correlations were assessed using Fisher＇s exact test. P values less than 0.05 on a 2-sided test were considered to be significant. Results Six- eight non-syndromic TOF children were screened for a 22q11. 2 deletion, among which 59 （86. 8%） presented pulmonary stenosis （PS） and 9 （13.2 %） presented pulmonary atresia （PA）. Seven patients （10. 3%） were found to have carried a deletion. Among these, four had TOF-PS, three had TOF-PA. The frequency of 22q11.2 deletion in patients with TOF-PA （3/9, 33.3 %） is much higher than that of TOF-PS （4/59, 6.80%） （P〈0. 05）. Conclusion 22q11. 2 microdeletion is present in approximately 10. 3% of patients with non-syndromic TOF. The deletion tends to have a higher prevalence in patients with TOF-PA. 22q11. 2 deletion should be screened in non-syndromic TOF children and genetic counselling may be provided.