3号染色体呈单亲二体性而无其他异常表型的隐性遗传营养不良型大疱性表皮松解症1例  

Complete maternal isodisomy of chromosome 3 in a child with recessive dystrophic epidermolysis bullosa but no other phenotypic abnormalities

作　　者：Fassihi H. Wessagowit V J.A. McGrath 董平 

机构地区：[1]Genetic Skin Disease Group, St. John's Institute of Dermatology, St. Thomas'Hospital, Lambeth Palace Road, London SE1 7EH, United Kingdom Dr.

出　　处：《世界核心医学期刊文摘（皮肤病学分册）》2006年第12期36-37,共2页Digest of the World Core Medical JOurnals:Dermatology

摘　　要：The mechanobullous disease Hallopeau-Siemens recessive dystrophic epidermolysis bullosa (HS-RDEB) results from mutations in the typeVII collagen gene (COL7A1) on chromosome 3p21.31. Typically, there are frameshift, splice site, or nonsense mutations on both alleles. In this report, we describe a patient with HS-RDEB, who was homozygous for a new frameshift mutation, 345insG, in exon 3 of COL7A1. However, sequencing of parental DNA showed that although the patient’s mother was a heterozygous carrier of this mutation, the father’s DNA contained only wild-type sequence. Microsatellite marker analysis confirmed paternity and genotyping of 28 microsatellites spanning chromosome 3 revealed that the affected child was homozygous for every marker tested with all alleles originating from a single maternal chromosome 3. Thus, the HS-RDEB phenotype in this patient is due to complete maternal isodisomy of chromosome 3 and reduction to homozygosity of the mutant COL7A1 gene locus. To our knowledge, there are no published reports of uniparental disomy (UPD) in HS-RDEB; moreover, this case represents only the third example of UPD of chromosome 3 to be reported. The severity of the HS-RDEB in this case was similar to other affected individuals and no additional phenotypic abnormalitieswere observed, suggesting an absence of maternally imprinted genes on chromosome 3.The mechanobullous disease Hallopeau-Siemens recessive dystrophic epidermolysis bullosa (HS-RDEB) results from mutations in the typeVII collagen gene (COL7A1) on chromosome 3p21.31. Typically, there are frameshift, splice site, or nonsense mutations on both alleles. In this report, we describe a patient with HS-RDEB, who was homozygous for a new frameshift mutation, 345insG, in exon 3 of COL7A1. However, sequencing of parental DNA showed that although the patient s mother was a heterozygous carrier of this ...

关 键 词：染色体 隐性遗传 营养不良型大疱性表皮松解症 单亲二体性 表型 

分 类 号：R758.5[医药卫生—皮肤病学与性病学]