Chromosomal abnormalities study for anembryonic pregnancy by BACs-on-Beads technique.

OBJECTIVE: This study evaluated the BACs-on-Beads™ (BoBs) efficiency assay in detecting chromosomal anomalies in products of conception (POC) specimens associated with anembryonic pregnancy (AP) among Thai pregnant women. METHOD: Retrospective analysis applied the BoBs™ assay to examine AP samples from 2010 to 2022. The incidences of AP with chromosomal abnormalities were reported. RESULT: Assessment of villi from anembryonic pregnancy samples found normal chromosome complement in 50% of the cases, while the remainder showed chromosomal abnormalities. Trisomy 16 was found in 15% of the cases and trisomies 22, 15, and 19 in 9.6%, 3.8%, and 3.8%, respectively. Advanced maternal age was associated with a higher incidence of aneuploidy. CONCLUSION: The BoBs™ assay effectively detected diverse chromosomal abnormalities in villi samples from POC. The diagnostic utility of the BoBs™ assay was highlighted in identifying chromosomal irregularities in AP cases. Trisomy 16 possessed the most chromosomal abnormalities in the AP samples.

Incidence and Types of Fetal Chromosomal Abnormalities in First Trimester of Thai Pregnant Women between Miscarriages and Intrauterine Survivals.

Abortion is a common pregnancy complication. Fetuses with several types of chromosomal abnormalities are aborted during the first trimester, while others have a better chance of surviving. This research aims to study and compare the incidence and types of fetal chromosomal abnormalities during the first trimester of Thai pregnant women between miscarriages and intrauterine survivals. Cytogenetic and BACs-on-Beads™ assays were assessed from 2010 to 2020 in Ramathibodi Hospital using first trimester samples of 265 chorionic villi as a retrospective study. Chromosomal abnormalities were observed in 135 cases (50.94%) including 38.11% miscarriages and 12.83% intrauterine survivals. In total, 75.56% single autosomal trisomies, 18.52% sex chromosome aneuploidies, 5.19% double aneuploidies, and 0.74% structural abnormalities were detected. In miscarriages, all chromosomes were involved in abnormalities except chromosomes 1, 5, 8, 9, 11, and 17, while survivals had only trisomy 13, 18, 21, and sex chromosome aneuploidy. Trisomy 16 and 18 were the most common abnormalities in miscarriages and intrauterine survivals, respectively. The highest rate of chromosomal aberrations was demonstrated in 8-9+6 and 12-13+6 weeks of gestation in miscarriages and intrauterine survivals, respectively. Correlation between chromosomal abnormalities and maternal age <35 years and ≥35 years was significant (p < 0.05) in intrauterine survival and first trimester groups.

Klinefelter Syndrome Mosaicism 46,XX/47,XXY: A New Case and Literature Review.

Most cases of Klinefelter syndrome (KS) have 47,XXY karyotype. We reported the first case of 46,XX/47,XXY KS whose genital ambiguity was detected prenatally with postnatal confirmation of the mosaicism and ovotesticular disorder of sex development (OT-DSD). The paternal origin of the extra X chromosome was identified using trio cytogenomic single-nucleotide polymorphism array. Additional 18 cases were also reviewed. The clinical presentation of 46,XX/47,XXY is age-dependent with two age peaks, including ambiguous genitalia during infancy and gynecomastia with or without cyclical hematuria and left scrotal pain and mass in adolescence. The 46,XX is the predominant karyotype both in peripheral blood and gonadal tissue. The risk of germ cell tumor is very high throughout life in these individuals. Individuals with 46,XX/47,XXY mosaicism should be treated more as OT-DSD other than a simple mosaic KS. A multidisciplinary approach and long-term monitoring are necessary.

Intrauterine growth retardation fetus with trisomy 16 mosaicism.

Fetal trisomy 16 is considered uniformly lethal early in gestation. It has been reported to be associated with the variability of clinical features and outcomes. Mosaic trisomy 16 leads to a high risk of abnormality in prenatal cases. Intrauterine growth retardation (IUGR) is a common outcome of mosaic trisomy 16. Herein, we report on the case of Thai male IUGR fetus with trisomy 16 mosaicism. The fetal body was too small. Postmortem investigation of placenta revealed the abnormality including small placenta with furcated cord insertion and single umbilical cord artery. Cytogenetic study demonstrated trisomy 16 that was found 100% in placenta and only 16% in the fetal heart while other organs had normal karyotype. In addition, cardiac and other internal organs examination revealed normal morphology.