目的　探讨12p三体新生儿的临床及细胞分子遗传学特点。方法　回顾1例经外周血行淋巴细胞常规G显带染色 体核型分析，高通量测序染色体组拷贝数分析（CNV）并经淋巴细胞间期荧光原位杂交（FISH）技术确认的12p三体新生儿的 临床资料。结果　患儿外周血染色体核型为47，XX，+mar，父母染色体核型均正常；CNV检出患儿12p13.33- p11.1 （160 001~ 34 860 000）区域重复，片段大小为34.7 Mb；外周血淋巴细胞间期FISH显示患儿所有间期细胞核12号染色体短臂均存在3个信号， 无嵌合体存在。确诊为12p三体。结论　结合临床特征、外周血染色体核型分析、CNV及FISH技术可有效确诊12p三体。

Objective　To explore the clinical features, cytogenetic and molecular genetics characteristics of trisomy 12p in neonates. Method　The clinical data were reviewed in a neonate with trisomy 12p confirmed by routine G-banding chromosome karyotype analysis, high throughput sequencing chromosome copy number variation analysis (CNV) and lymphocyte interphase fluorescence in situ hybridization (FISH). Results　The chromosome karyotype in peripheral blood of the neonate was 47,XX,+mar, and the karyotypes of her parents were normal. CNV detected a regional duplication of 12 p13.33-p11.1 (16000134860000) with a fragment size of 34.7 Mb. Peripheral blood lymphocyte interphase FISH showed that there were 3 signals in the short arm of chromosome 12 in all interphase nuclei of the neonate, and no chimera existed. It was finally confirmed to be trisomy 12p. Conclusion　The combination of clinical features, peripheral blood karyotype analysis, CNV and FISH techniques can effectively confirm the diaganosis of trisomy 12p .