{Reference Type}: Case Reports
{Title}: [Genetic analysis of a case with a supernumerary marker derived from chromosome 9].
{Author}: Zhuang Q;Yan M;Jiang Y;Chen X;Zhang N;Lyu C;Wu J;Wang Y;
{Journal}: Zhonghua Yi Xue Yi Chuan Xue Za Zhi
{Volume}: 39
{Issue}: 12
{Year}: Dec 2022 10
暂无{DOI}: 10.3760/cma.j.cn511374-20211027-00854
{Abstract}: <B>OBJECTIVE: </B>To delineate a small supernumerary marker chromosome (sSMC) derived from chromosome 9 with combined cytogenetic and molecular methods.<BR><B>METHODS: </B>For a pregnant woman with fetal ultrasound revealing left ventricular punctate hyperechoic echo, and a high risk for monosomy or partial deletion of chromosome 8, chromosome 9 trisomy, monosomy or partial deletion of chromosome 11 by non-invasive prenatal testing, and an abnormal MOM value revealed by mid-term serum screening, amniocentesis was performed for G banded chromosomal analysis and single nucleotide polymorphism array (SNP-array) assay. Peripheral blood samples of the woman and her spouse were also collected for the above tests. In addition, the woman was further subjected to C banding karyotyping analysis and fluorescence in situ hybridization (FISH) assay.<BR><B>RESULTS: </B>The G-banded karyotype of the pregnant women was 47,XX,+mar[20]/46,XX[80], whilst C-banding analysis showed a deep stain in the middle of the sSMC (suggestive of centromeric region) and light stain at both ends (suggestive of euchromatism). FISH combined with DAPI banding analysis using 9pter/9qter probes revealed a karyotype of 47,XX,+mar.ish i(9)(9p10)(9p++)[2]/46,XX[18], whilst SNP-array has revealed a 68.1 Mb duplication in the 9p24.3q13 region. A database search has suggested the duplication to be likely pathogenic. No abnormality was found in her fetus and spouse by karyotyping and SNP-array analysis.<BR><B>CONCLUSIONS: </B>Through combined cytogenetic and molecular genetic analysis, a sSMC derived from chromosome 9 was delineated, which has enabled genetic counseling for the couple.