Cohen O, Mermet M A, Cans C, Gilardi J L, Simonet A, Jalbert P
Equipe de Génétique Constitutionnelle, TIMC, Faculté de Médecine de Grenoble, La Tronche, France.
Ann Genet. 1995;38(4):177-86.
Reciprocal translocations are one of the most frequently observed structural chromosome abnormalities. They are defined by a segment exchange between two non-homologous chromosomes. A great number of different translocations exist since any chromosome can be involved in the translocation and the position of the breakpoint can vary. Though generally silent these translocations can be expressed in the form of reproduction failure or, more seriously, as offspring showing mental retardation/malformation syndromes. Since the risk of malformation varies from one translocation to the next, genetic counselling and prenatal diagnosis strategies should be adopted to suit the particular malformation risks of each individual translocation. This is currently not the case. Different prediction methods (for the most probable mode of unbalance at birth, the risk of unbalance at term) are presented. A computer system, called Reci-Conseil brings these different functionalities together to create a new aid for genetic counselling. The data base on which it is founded (approx 2000 families) offers interesting perspectives for genomic mapping of partial trisomies and monosomies.
相互易位是最常观察到的染色体结构异常之一。它们由两条非同源染色体之间的片段交换所定义。由于任何染色体都可能参与易位且断点位置可以不同，所以存在大量不同的易位情况。虽然这些易位通常不表现出症状，但可能以生殖失败的形式表现出来，或者更严重的是，后代会出现智力发育迟缓/畸形综合征。由于不同易位导致畸形的风险各不相同，因此应采用遗传咨询和产前诊断策略，以适应每种特定易位的畸形风险。目前情况并非如此。本文介绍了不同的预测方法（针对出生时最可能的失衡模式、足月时的失衡风险）。一个名为Reci-Conseil的计算机系统将这些不同功能整合在一起，为遗传咨询提供了新的辅助工具。其建立所依据的数据库（约2000个家庭）为部分三体和单体的基因组图谱绘制提供了有趣的视角。
