Misdiagnosis of mosaic tetrasomy 9p in a fetus by single nucleotide polymorphism-based array.
- VernacularTitle:单核苷酸多态微阵列芯片误诊9p四体嵌合体胎儿一例
- Author:
Jianzhu WU
1
;
Yingjun XIE
;
Baojiang CHEN
Author Information
- Publication Type:Case Reports
- MeSH: Adult; Amniocentesis; methods; Aneuploidy; Chromosome Banding; Chromosome Disorders; diagnosis; genetics; Chromosomes, Human, Pair 9; Diagnostic Errors; Female; Fetal Growth Retardation; diagnosis; genetics; Humans; Infant, Newborn; Karyotyping; Male; Mosaicism; Oligonucleotide Array Sequence Analysis; methods; Polymorphism, Single Nucleotide; Pregnancy; Pregnancy Outcome; Trisomy
- From: Chinese Journal of Medical Genetics 2015;32(6):830-833
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo explore the reason for discordant results of karyotyping and microarray analysis in a fetus with mosaic tetrasomy 9p.
METHODSAmniocentesis was carried out for a pregnant woman with advanced age for whom ultrasound scan has indicated fetal ventricular expansion, intrauterine growth retardation and persistent upper venous cavity. G-banded karyotyping and single nucleotide polymorphism-based arrays (SNP-array) analysis were performed at the same time.
RESULTSAnalysis of amniocytic chromosome has suggested mosaic tetrasomy 9p (47,XX,+psu idic(9)(q21)[23]/46,XX[27]). While SNP-array has detected a non-mosaic trisomy 9p with a 68.7 Mb duplication at 9p24.3q21.11. The results of the two methods were therefore discordant.
CONCLUSIONSNP-array will analyze genetic material in the form of numbers rather than morphology. For chimeras containing two types of cell lines, when the mosaic rate was close to 50% and the average amount of genetic material of the chimeras was equivalent to the amount of genetic material of non-chimeras, microarray analysis may come to the conclusion of a non-mosaic heteroploidy. Therefore, microarray results for large segment chromosome abnormalities should be combined with the results of G-banded karyotyping for genetic counseling.
