一例由染色体不平衡易位t(5;15)导致的Prader-Willi综合征

目的 对1例临床疑似Prader-willi综合征(Prader-Wil syndrome,PWS)的患儿进行遗传学诊断和分型.方法 应用染色体核型分析结合甲基化特异性PCR(methylation-specific PCR,MS-PCR)及短串联重复序列(short tandem repeat,STR)家系连锁分析方法对患儿进行诊断和分子病理学分型.结果 患儿染色体核型为45,XX,der(5)t(5;15)(q35;q13),-15,存在5号与15号染色体之间的不平衡易位;甲基化特异性PCR及STR家系连锁分析方法进一步证实患儿为父源15号染色体不平衡易位导致的15q缺失型Prader-Willi综合征.结论 临床疑似PWS的患儿应进行遗传学检查,以便获得确诊.细胞遗传学及分子遗传学方法的有效结合对于临床诊断、分辨不同病理类型、遗传咨询以及产前诊断都具有积极的作用.

Unbalanced translocation t (5;15) in a patient with Prader-Willi syndrome

Objective To diagnose and detect the molecular defect in a suspected patient with Prader-Willi syndrome. Methods Genetic diagnosis and molecular genetic analysis were performed by using chromosome karyotype analysis, methylation-specific PCR (MS-PCR), and linkage analysis using short tandem repeat (STR). Results The karyotype of the patient was 45,XX, der (5), t (5;15)(q35;q13),-15, and the parents were 46,XY and 46, XX , respectively, implying that the unbalanced translocation t(5;15) in the patient was de novo. Furthermore, MS-PCR and STR linkage analysis confirmed that the patient's 15q11-13 deletion was resulted from unbalanced translocation on paternal chromosome 15.Conclusion Genetic analysis should be applied in suspected patients with Prader-Willi syndrome to confirm the diagnosis. Cytogenetic and molecular techniques would be helpful in clinical diagnosis, genetic counseling and prenatal diagnosis.