摘要目的：探讨单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP array)在Angelman 综合征(Angelman syndrome,AS)基因型与表型对应分析中的应用。方法对1例临床表现为先天畸形、智力低下、发育迟缓等异常的患儿及其父母行外周血染色体核型分析和 SNP array 检测,同时用基于 SNP 信号的孟德尔遗传错误校验进行家系传递分析,之后用荧光原位杂交(fluorescence in situ hybridization,FISH)检测验证 SNP array 结果。结果患儿 SNP array 结果显示15q11.2q13.1(22770421~28823722)存在6.053 Mb 缺失,与1型缺失型 AS 关键区域完全重叠。患儿父母染色体核型、SNP array 及 FISH 检测结果均未见异常,表明15q11.2q13.1缺失为新发的变异。家系孟德尔遗传错误校验结果提示患儿15q11.2q13.1缺失为母源性片段缺失。结论SNP array 可以精确地分析15q11q13缺失片段的大小、断裂点及其亲源性,从而有效地诊断缺失型 AS,促进 AS 基因型与表型的对应关系分析。

abstractsObjective To analyze a case with Angelman syndrome (AS)using single nucleotide polymorphism array (SNP array)and explore its genotype-phenotype correlation.Methods G-banded karyotyping and SNP array were performed on a child featuring congenital malformations,intellectual disability and developmental delay.Mendelian error checking based on the SNP information was used to delineate the parental origin of detected abnormality. Result of the SNP array was validated with fluorescence in situ hybridization (FISH).Results The SNP array has detected a 6.053 Mb deletion at 1 5q1 1.2q13.1 (22,770,421-28,823,722)which overlapped with the critical region of AS (type 1 ).The parents of the child showed no abnormal results for G-banded karyotyping,SNP array and FISH analysis, indicating a de novo origin of the deletion.Mendelian error checking based on the SNP information suggested that the 1 5q1 1.2q13.1 deletion was of maternal origin.Conclusion SNP array can accurately define the size,location and parental origin of chromosomal microdeletions,which may facilitate the diagnosis of AS due to 1 5q1 1q13 deletion and better understanding of its genotype-phenotype correlation.