Abstract:

We report a family with a history of multiple adverse reproductive outcomes due to a balanced chromosomal translocation. The clinical data and blood samples of the family's members were collected. Chromosomal karyotype and single nucleotide polymorphism array (SNP array) analysis were performed. The proband (female) presented with language developmental delay, intellectual disability, epilepsy and other manifestations, while her younger brother displayed a similar phenotype. The mother sought genetic counseling at 8⁺² weeks of gestation. Karyotype analysis revealed that the father was a carrier of a balanced translocation, t(8;13)(p23;q22), and SNP array testing showed a microdeletion in 16p13.11p12.3. The karyotype and SNP array results of mother were normal. Both the proband and her brother had the karyotype being consistent with the father's translocation, and the SNP array results being an 8p23.3 deletion and a 13q31.1q34 duplication. Additionally,the proband inherited the father's 16p13.11p12.3 microdeletion. At 12⁺² weeks of the current pregnancy, the ultrasound revealed multiple abnormalities in the fetus, including increased nuchal translucency (NT) thickness. The pregnancy ended in embryonic demise at 14 weeks, and no genetic testing was performed. The 8p23.3 deletion and 13q31.1q34 duplication were responsible for the abnormal phenotypes in the proband and her brother. Although not tested, the two spontaneous miscarriages and this embryonic arrest may share the same underlying cause. Therefore, the couples where one partner is a balanced translocation carrier require genetic counseling and prenatal diagnosis.

Key words: Translocation, genetic, Polymorphism, single nucleotide, Karyotyping, Microarray analysis, Pregnancy outcome