Sotos综合征患儿的遗传学分析

Genetic analysis of a child with Sotos syndrome

目的对1例智力低下患儿进行遗传学分析,明确患儿的遗传学病因。方法对1例智力低下患儿行G显带染色体核型分析、单核昔酸多态性微阵列(single nucleotide polymorphism array,SNParray)及荧光原位杂交(fluorescence in situ hybridization,FISH)检测,患儿父母行外周血染色体核型及FISH分析。结果SNP-array分析显示患儿染色体5q35.2q35.3存在5077 kb缺失,7q36.2q36.3存在4964 kb重复,FISH验证了SNP-array的结果。根据患儿SNP-array和FISH结果及其父母外周血FISH结果,确认胎儿父亲为隐匿性t(5;7)(q35.2;q36.2)携带者,而胎儿遗传了其中一条衍生的5号染色体der(5)t(5)7)(q35.2;q3&2)。结论5q35.2q35.3微缺失对Sotos综合征表型的产生起主导作用,SNParray结合FISH技术有助于发现染色体隐匿性易位。

Objective To explore the genetic basis for a child with mentally retardation.Methods G-banding karyotyping,single nucleotide polymorphism array(SNP-array)and fluorescence in situ hybridization(FISH)were performed for the child.Karyotyping and FISH were also carried out for her parents.Results SNP-array has detected a 5077 kb microdeletion at 5q35.2q35.3 and a 4964 kb microduplication at 7q36.2q36.3 in the child.The results were confirmed by FISH.Based on above results,the father was subsequently found to carry a cryptic t(5;7)(q35.2;q36.2)translocation.The child was verified to have inherited a der(5)t(5;7)(q35.2;q36.2)from her father.Conclusion The 5077 kb microdeletion at 5q35.2q35.3 may have predisposed to the Sotos syndrome in the child.SNP-array combined with G-banding karyotyping and FISH can help to detect cryptic chromosomal translocations among patients.