Genetic analysis and prenatal diagnosis for a pregnant woman with an unbalanced t(1;2), t(6;7) translocation and intellectual disability / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To provide genetic analysis for a pregnant woman with chromosomal translocations and intellectual disability, and to provide prenatal diagnosis for her fetus.</p><p><b>METHODS</b>Routine G-banding was performed to analyze the karyotypes of the woman and her fetus. Copy number variants were determined with array comparative genomic hybridization (array-CGH).</p><p><b>RESULTS</b>The pregnant woman has carried an apparently balanced translocation involving chromosomes 1, 2, 6 and 7, with a karyotype of 46, XX, t(1;2) (p22;p23), t(6;7) (q21;p15). The karyotype of her fetus was ascertained as 46, XY, t(6;7) (q21;p15) mat. Array-CGH has detected a 4 Mb microdeletion at 6q22.1-q22.31 (115 311 507-119 332 956) in both individuals. As the 6q22.1-q22.31 microdeletion may be associated with the main clinical manifestations of the woman, the family decided to terminate the pregnancy. The fetus was male and appeared to have no obvious abnormality.</p><p><b>CONCLUSION</b>Prenatal diagnosis for pregnant women with translocations and mental retardation is a challenging task. Combined application of cytogenetic analysis and array-CGH may facilitate the diagnosis and genetic counseling.</p>