Prenatal diagnosis of 45,X/46,XY mosaicism with cleft lip and epispadias

Prenatal diagnosis of BACs-on-Beads assay in 1520 cases from Fujian Province, China

Background

The aim of this study was to evaluate the application of BACs‐on‐Beads (BoBs™) assay for rapid detection of chromosomal abnormalities for prenatal diagnosis (PND).

Methods

A total of 1520 samples, including seven chorionic villi biopsy samples, 1328 amniotic fluid samples, and 185 umbilical cord samples from pregnant women were collected to detect the chromosomal abnormalities using BoBs™ assay and karyotyping. Furthermore, abnormal specimens were verified by chromosome microarray analysis (CMA) and fluorescence in situ hybridization (FISH).

Results

The results demonstrated that the success rate of karyotyping and BoBs™ assay in PND was 98.09% and 100%, respectively. BoBs™ assay was concordant with karyotyping for Trisomy 21, Trisomy 18, and Trisomy 13, sex chromosomal aneuploidy, Wolf–Hirschhorn syndrome, and mosaicism. BoBs™ assay also detected Smith–Magenis syndrome, Williams–Beuren syndrome, DiGeorge syndrome, Miller–Dieker syndrome, Prader–Willi syndrome, Xp22.31 microdeletions, 22q11.2, and 17p11.2 microduplications. However, karyotyping failed to show these chromosomal abnormalities. A case of 8q21.2q23.3 duplication which was found by karyotyping was not detected by BoBs™ assay. Furthermore, all these chromosomal abnormalities were consistent with CMA and FISH verifications. According to the reports, we estimated that the detection rates of karyotyping, BoBs™, and CMA in the present study were 4.28%, 4.93%, and 5%, respectively, which is consistent with the results of a previous study. The respective costs for the three methods were about $135–145, $270–290, and $540–580.

Conclusion

BoBs™ assay is considered a reliable, rapid test for use in PND. A variety of comprehensive technological applications can complement each other in PND, in order to maximize the diagnosis rate and reduce the occurrence of birth defects.

45,X mosaicism in northeast China: a clinical report and review of the literature

Purpose

To explore the prevalence and clinical features, especially the reproductive function, of 45,X mosaicism patients in northeast China.

Methods

GTG-banding was performed on a series of 2,250 patients from our genetic counseling clinic. Each of these patients underwent a physical examination and was interviewed about their medical history and reproductive problems. Literature on 45,X mosaicism was accessed using PubMed and reviewed.

Results

The prevalence of 45,X mosaicism in northeast China is 0.36 % (8/2250), and the mosaic karyotype of our study accounted for 61.54 % (8/13) of Turner syndrome cases. This is comparable with studies from Asia, Europe, South America and other regions. The affected patients showed genital abnormalities, abnormal pregnancy or infertility.

Conclusion

45,X mosaicism is commonly seen in the genetic counseling clinic. Extensive cytogenetic assessment may improve the detection rate in patients with congenital dysplasia, or history of abnormal pregnancy or infertility. Karyotyping plays a key role in prognosis and assisted reproduction or early surgical treatment.