Pazarbaşi A, Demirhan O, Turgut M, Güzel I, Taştemir D
Department of Medical Biology and Genetics, Faculty of Medicine, University of Cukurova, Turkey.
Genet Couns. 2008;19(3):301-8.
Reciprocal translocation carriers have reduced fertility, increased risk of spontaneous abortion or unbalanced karyotype in their offspring. Here, we report the inheritance of a translocation between chromosomes 12 and 16 in a family with recurrent miscarriages and a newborn with Down syndrome carrying the same translocation. Chromosomal analysis from fetal amniotic fluid and peripheral blood lymphocytes from the family were performed at the Cukurova university hospital in Turkey. We assessed a family in which the translocation between chromosomes 12 and 16 segregates; one of the eight progenies with the karyotype 47,XY,+21,t(12;16)(q24;q24) was heterozygote for the translocation and presented with Down syndrome. His mother is phenotypically normal, one brother and one sister were also carrying the same translocation. Apparently, this rearrangement occurred due to the unbalanced chromosome segregation of the mother [t(12;16)(q24;q24)mat]. This case will enable us to explain the behavior of segregation patterns and the mechanism for each type oftranslocation from carrier to carrier and their effects on reproduction and numerical aberrations. The t(12;16) is also associated with fetal wastage and may play a role in the etiology of the family's miscarriages. These findings can be used in clinical genetics and may be used as an effective tool for reproductive guidance and genetic counseling.
相互易位携带者的生育能力降低，其后代出现自然流产或核型不平衡的风险增加。在此，我们报告了一个反复流产的家庭中12号和16号染色体之间易位的遗传情况，以及一名患有唐氏综合征的新生儿也携带相同的易位。在土耳其的库库罗瓦大学医院对该家庭的胎儿羊水和外周血淋巴细胞进行了染色体分析。我们评估了一个12号和16号染色体之间易位分离的家庭；核型为47,XY,+21,t(12;16)(q24;q24)的八个后代之一是易位杂合子，并患有唐氏综合征。他的母亲表型正常，一个哥哥和一个姐姐也携带相同的易位。显然，这种重排是由于母亲的染色体分离不平衡[t(12;16)(q24;q24)mat]所致。这个病例将使我们能够解释分离模式的行为以及每种类型的易位从携带者到携带者的机制及其对生殖和数目畸变的影响。t(12;16)也与胎儿丢失有关，可能在该家庭流产的病因中起作用。这些发现可用于临床遗传学，并可作为生殖指导和遗传咨询的有效工具。
