Woodage T, Prasad M, Dixon J W, Selby R E, Romain D R, Columbano-Green L M, Graham D, Rogan P K, Seip J R, Smith A
Department of Molecular Genetics, Royal Prince Alfred Hospital, Camperdown, New South Wales.
Am J Hum Genet. 1994 Jul;55(1):74-80.
Bloom syndrome (BS) is an autosomal recessive disorder characterized by increases in the frequency of sister-chromatid exchange and in the incidence of malignancy. Chromosome-transfer studies have shown the BS locus to map to chromosome 15q. This report describes a subject with features of both BS and Prader-Willi syndrome (PWS). Molecular analysis showed maternal uniparental disomy for chromosome 15. Meiotic recombination between the two disomic chromosomes 15 has resulted in heterodisomy for proximal 15q and isodisomy for distal 15q. In this individual BS is probably due to homozygosity for a gene that is telomeric to D15S95 (15q25), rather than to genetic imprinting, the mechanism responsible for the development of PWS. This report represents the first application of disomy analysis to the regional localization of a disease gene. This strategy promises to be useful in the genetic mapping of other uncommon autosomal recessive conditions.
布卢姆综合征（BS）是一种常染色体隐性疾病，其特征是姐妹染色单体交换频率增加以及恶性肿瘤发病率上升。染色体转移研究表明，BS基因座定位于15号染色体长臂（15q）。本报告描述了一名同时具有BS和普拉德-威利综合征（PWS）特征的患者。分子分析显示该患者15号染色体存在母源单亲二体性。两条二体性15号染色体之间的减数分裂重组导致15q近端的异二体性和15q远端的同二体性。在该个体中，BS可能是由于D15S95（15q25）端粒处一个基因的纯合性所致，而非由于负责PWS发生的遗传印记机制。本报告代表了二体性分析在疾病基因区域定位中的首次应用。该策略有望在其他罕见常染色体隐性疾病的基因定位中发挥作用。
