Conventional and molecular cytogenetic analyses of a derivative X chromosome in amniocentesis / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To analyze the aberrant der(X) chromosome using conventional and molecular cytogenetic approaches in a fetus of second trimester and to discuss its clinical effect.</p><p><b>METHODS</b>Conventional cytogenetic procedures (GTG and CBG banding) were performed on cultured amniotic fluid cells. Three-color fluorescence in situ hybridization (FISH) consisting of X chromosome enumeration probes(CEPX), CEPY and Tel Xp/Yp was further performed to study the aberrant der(X) chromosome.</p><p><b>RESULTS</b>Der(X) was a rare X/Y translocation. The final karyotypes of the fetus was designated as 46,X,der(X)t(X;Y)(p22.3;q11.2). ish der(X)t(X;Y)(p22.3;q11.2)(X/Ypter-, DXZ1+, DYZ1+)mat.</p><p><b>CONCLUSION</b>The combination of FISH and conventional cytogenetic techniques is a powerful tool to determine derivative chromosome and to offer an accurate genetic counseling. Identification of Xp; Yq rearrangement can help estimate the risk of fetus abnormalities and give a more precise prognosis.</p>