Prenatal diagnosis of a fetus with partial trisomy 8p resulting from a balanced maternal translocation by array-based comparative genomic hybridization
To determine the karyotype of a fetus with transverse aortic arch hypoplasia, and to investigate the feasibility of array-based comparative genomic hybridization (array-CGH) for molecular genetic diagnosis. G-banding was performed to analyze the karyotypes of the fetus and its parents, and array-CGH was applied to identify the chromosomal abnormality of the fetus. G-banding analysis revealed that the pregnant woman has carried a balanced translocation 46,XX, t(8;16)(p21;q24), while the fetus has carried an unbalanced translocation 46,XX,der(16)t(8;16)(p21;q24)mat. Array-CGH analysis suggested that the derivative chromosomal fragment has originated from 8p with breakpoints in 8p23.3-p21.3. Trisomy 8p23.3-p21.3 may have predisposed to transverse aortic arch hypoplasia in the fetus. Parental karyotype analysis could help to characterize the translocation and evaluate the recurrent risk. Compared with routine karyotype analysis, aCGH has a higher resolution and greater accuracy for mapping chromosomal aberrations.