A Study on the Translocation of Human Chromosome / 대한주산의학회잡지

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the relation between the chromosomal translocation and the outcome of pregnancy. METHODS: Between 1989 and 2001, 26 translocation carriers have been detected in our center and Jin Obstetrics and Gynecology Clinic. The subjects consisted of 26 couples that included 14 reciprocal translocation carriers and 12 Robertsonian translocation carriers. The balanced translocation carriers were analyzed retrospectively. RESULTS: The most frequent indication for parental chromosomal examination was repeated abortions or fetal death(57.7%). In contrast to couples with reciprocal translocations, a high excess of female over male carriers was found in the group of Robertsonian translocations. The rates of miscarriages (68.0%) in prior pregnancies were significantly higher than the birth rates of morphologically normal newborns(16.0%). Prenatal chromosomal examination in subsequent pregnancies revealed that 24.0% of the fetuses showed normal karyotypes, 56.0% of the fetuses showed balanced translocations and 20.0% of the fetuses showed a chromosomal imbalance. The unbalanced karyotypes consisted of three trisomies, one partial trisomy and one duplication. There was no case of partial monosomy in this study. CONCLUSIONS: The risk of unbalanced chromosome abnormalities was greater in our study than the empirically known risk. Prenatal examination is always indicated in carriers of any type of translocation.