12p部分三体的细胞-分子遗传学及表型定位研究  

Cytogenetic and molecular genetics and phenotype analysis of a patient with partial trisomy 12p

作　　者：张亚男[1,2] 曾艳红[3] 宋新明[1] 梁秀龄[4] 陈争[1] 

机构地区：[1]中山大学中山医学院医学遗传教研室,广州510080 [2]中山大学附属第三医院不育与性医学科 [3]中山大学附属第一医院生殖医学中心 [4]中山大学附属第一医院神经内科

出　　处：《中国神经精神疾病杂志》2011年第12期744-748,共5页Chinese Journal of Nervous and Mental Diseases

基　　金：国家自然科学基金(编号:30971601);广东省自然科学基金(编号:9151008901000089);广东省科技计划项目(编号:2010B031600039)

摘　　要：目的进一步探讨12p部分三体综合征遗传物质增加与临床表现之间的关系。方法我们对1例具有发育缓慢、精神发育迟滞和面部畸形的13个月大患儿和双亲进行了包括G显带、高分辨和荧光原位杂交(fluorescence in situ hybridization,FISH)分析,同时对包括文献报道的24例12p部分三体进行表型定位分析。结果患者的12p部分三体来源于母亲的平衡易位,小睑的发生可能与剂量关系不大,而是12p13区域存在与眼睑发育有关的基因簇,染色体断裂后直接或者间接的影响了他们的表达或功能,导致眼睑发育异常。结论 12p部分三体的典型症状与特定染色体区域的基因表达或功能有关。Objective The aim of this research is to narrow down the genetic abnormalities of the trisomy 12p syndrome in order to identify the candidate gene of the disease.Methods a 13-month old boy with mental retardation and the characteristic facial appearance of patients with the trisomy 12p syndrome was examined.To address whether the child possessed three copies of 12p or a portion of 12p region,we determined the patients karyotype using cytogenetics methodologies,including the conventional G-banding,high resolution banding,and fluorescence in situ hybridization（FISH） methods.The patient＇s parents＇ karyotypes were also examined.Results The infant＇s partial trisomy 12p was originated from his mother＇s balanced translocation.These defects in eyelid development might be resulted from de novo chromosome abnormalities with the insertion sites of a trisomy fragment（repeating fragment） being at either 12p13.2 or 13.1,as these patients＇ parents all display normal karyotype.Because patients with complete trisomy 12p or their chromosome breaking points of trisomy 12p that lie outside the 12p13 region did not show small eyelid or without eyelid.Taken together,it was tempting to conclude that these defects in eyelid development might not be caused by changes in gene doses,but rather resulted from breaking points occurred at the 12p13 region.These breaking points might affect the expression of critical genes that play essential roles during eyelid development.Conclusions The phenotype of trisomy 12p may be associated with express and function of gene at special chromosome region.Further examination of the existence of critical candidate genes whose abnormalities cause trisomy 12p syndrome will need to precisely map the break and insert sites involved in trisomy 12p.

关 键 词：12p三体综合征 荧光原位杂交 精神发育迟缓 小(眼)睑 

分 类 号：R725.9[医药卫生—儿科]