Genetic analysis of a case with a supernumerary marker derived from chromosome 9.
10.3760/cma.j.cn511374-20211027-00854
- Author:
Qianmei ZHUANG
1
;
Meizhen YAN
;
Yuying JIANG
;
Xinying CHEN
;
Na ZHANG
;
Chunling LYU
;
Jialing WU
;
Yuanbai WANG
Author Information
1. Center of Prenatal Diagnosis, Quanzhou Maternal and Child Health Care Hospital, Quanzhou Children's Hospital, Quanzhou, Fujian 362000, China. wybslj@163.com.
- Publication Type:Journal Article
- MeSH:
Female;
Humans;
Pregnancy;
Biomarkers;
Chromosomes, Human, Pair 9/genetics*;
Genetic Testing;
In Situ Hybridization, Fluorescence;
Monosomy
- From:
Chinese Journal of Medical Genetics
2022;39(12):1410-1414
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To delineate a small supernumerary marker chromosome (sSMC) derived from chromosome 9 with combined cytogenetic and molecular methods.
METHODS: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.
RESULTS: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.
CONCLUSION:Through combined cytogenetic and molecular genetic analysis, a sSMC derived from chromosome 9 was delineated, which has enabled genetic counseling for the couple.
