Chromosomal abnormality: Prevalence, prenatal diagnosis and associated anomalies based on a provincial-wide birth defects monitoring system

The Genetics of 241 Fetuses With Talipes Equinovarus: A 8-Year Monocentric Retrospective Study

OBJECTIVE

This study aims to investigate the utility of chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in fetuses diagnosed with talipes equinovarus (TE), as well as to explore the genetic factors contributing to TE.

METHODS

The study reviewed a total of 241 fetuses with TE between January 2015 and December 2023, categorizing them into two groups based on the absence or presence of additional ultrasound anomalies: 163 cases (67.6%) in the isolated TE group and 78 cases (32.4%) in the syndromic TE group. Karyotyping and CMA were performed for all cases, with WES being performed for 18 cases that had normal karyotype and CMA results.

RESULTS

The results indicated a total detection rate of 16.2% (39/241) using karyotyping and CMA. Furthermore, the detection rates of karyotyping and CMA in the isolated TE group and syndromic TE group were 10.4% (17/163) and 28.2% (22/78) respectively, showing a statistically significant difference (p < 0.05). WES was conducted on 18 fetuses with normal karyotyping and CMA results. A total of six cases, consisting of five cases with pathogenic single nucleotide variant (SNV) and one case of variants of uncertain significance (VUS), were identified, resulting in a detection rate of 33.3% (6/18). The identified SNVs was associated with the RIT1, GNPNAT1, PEX1, RYR1, ASCC1, and GDAP1 genes. The detection rates of WES in the isolated TE group and syndromic TE group were 25% (1/4) and 35.7% (5/14) respectively, with no statistically significant difference (p > 0.05). The overall diagnostic yield of genetic testing was 18.7% (45/241) in fetuses with TE.

CONCLUSION

When prenatal ultrasound identifies fetal TE, chromosome karyotyping and CMA should be considered as the first-line diagnostic tests. Unlike previous studies, this study recommended WES in cases of normal CMA results for both isolated and syndromic fetal TE.

Systematic review and meta-analysis of the association between young maternal age and fetal abnormalities

Fetal anomalies among young women and adolescents pose major public health concerns. This systematic review aims to elucidate the relationship between young maternal age and the incidence of fetal abnormalities. According to the systematic review and meta-analysis PRISMA protocol, cohort, cross-sectional and case-control studies were scrutinized to include 80,393,450 participants across diverse regions. The meta-analysis utilized Odds Ratios (OR) as the effect measure, adopting a random-effects model. The screening process involved 157 selected and verified manuscripts, which ultimately resulted in the final inclusion of 20 studied in the meta-analysis. The criterion for young maternal age was the age of ≤ 20 years. The meta-analysis revealed a pooled OR of 0.93 (95% CI: 0.82-1.05, p = 0.252), indicating no statistically significant association between young maternal age (≤ 20 years) and fetal anomalies. However, considerable heterogeneity (I² = 96.21%) was noted, prompting the use of a random-effects model to derive the reported results. The meta-analysis did not find statistically significant differences in the occurrence of congenital anomalies in fetuses of younger women than in overall population. Although due to significant heterogeneity of the analyzed studies, and a risk of bias, caution should be exercised when interpreting the results, further investigation may be warranted to understand the relationship between maternal age and risk of fetal anomalies. Nevertheless, the study shows significant differences, which diminish in collective analysis, suggests that factors beyond age may be influential. Specifically, the limited access to or quality of healthcare in certain regions could be a more critical factor than maternal age itself.

Maternal Exposure to Per- and Polyfluoroalkyl Substances and Offspring Chromosomal Abnormalities: The Japan Environment and Children's Study

BACKGROUND

Although recent in vitro experimental results have raised the question of whether maternal exposure to per- and polyfluoroalkyl substances (PFAS) may be a potential environmental risk factor for chromosomal abnormalities, epidemiological studies investigating these associations are lacking.

OBJECTIVES

This study examined whether prenatal PFAS exposure is associated with a higher prevalence of chromosomal abnormalities among offspring.

METHODS

We used data from the Japan Environment and Children's Study, a nationwide birth cohort study, and employed logistic regression models to examine the associations between maternal plasma PFAS concentrations in the first trimester and the diagnosis of chromosomal abnormalities in all births (artificial abortions, miscarriages, stillbirths, and live births) up to 2 years of age. In addition, we examined associations with mixtures of PFAS using multipollutant models.

RESULTS

The final sample consisted of 24,724 births with singleton pregnancies, of which 44 confirmed cases of chromosomal abnormalities were identified (prevalence: 17.8/10,000 births). When examined individually, exposure to perfluorononanoic acid (PFNA) and perfluorooctane sulfonic acid (PFOS) showed positive associations with any chromosomal abnormalities with age-adjusted odds ratios of 1.81 (95% CI: 1.26, 2.61) and 2.08 (95% CI: 1.41, 3.07) per doubling in concentration, respectively. These associations remained significant after Bonferroni correction, although they did not reach the adjusted significance threshold in certain sensitivity analyses. Furthermore, the doubling in all PFAS included as a mixture was associated with chromosomal abnormalities, indicating an age-adjusted odds ratio of 2.25 (95% CI: 1.34, 3.80), with PFOS as the predominant contributor, followed by PFNA, perfluoroundecanoic acid (PFUnA), and perfluorooctanoic acid (PFOA).

DISCUSSION

The study findings suggested a potential association between maternal exposure to PFAS, particularly PFOS, and chromosomal abnormalities in offspring. However, the results should be interpreted cautiously, because selection bias arising from the recruitment of women in early pregnancy may explain the associations. https://doi.org/10.1289/EHP13617.

Evaluation of chromosomal abnormalities in the postnatal cohort: A single-center study on 14,242 patients

BACKGROUND AND AIM

Chromosomal analysis is a laboratory technique used to examine the chromosomes of an individual, offering insights into chromosome numbers, structures, and arrangements to diagnose and comprehend genetic diseases. This retrospective study provides a comprehensive understanding of the distribution by indications in a large cohort of 14,242 patients and the frequency of chromosomal abnormalities in different clinical populations.

METHOD

The study examined various indications for karyotype evaluation, with recurrent pregnancy loss being the most common indication, followed by intellectual disability, dysmorphic features, congenital anomalies, and developmental delay.

RESULTS

The overall chromosomal abnormality rate was found to be 5.4%, with numerical abnormalities accounting for the majority of cases (61.7%). Trisomies, particularly trisomy 21, were the most frequent numerical abnormalities. In terms of structural abnormalities, inversions and translocations were the most commonly identified. The rates of chromosomal anomalies varied in specific indications such as amenorrhea, disorders of sex development, and Turner syndrome. The study also highlighted significant differences between males and females in the presence of chromosomal abnormalities across certain indications. Males exhibited a higher incidence of chromosomal abnormalities in cases of Down syndrome and infertility, whereas females showed higher abnormalities in terms of recurrent pregnancy loss.

CONCLUSION

While this study provides valuable insights into the frequency and distribution of chromosomal abnormalities, it has limitations, including its retrospective design and reliance on data from a single medical genetics department. Nevertheless, the findings emphasize the importance of karyotype analysis in diagnosing chromosomal disorders and providing appropriate management, while also pointing to potential gender-related variations in chromosomal abnormalities that warrant further investigation.

Prevalence of co-occurring conditions in children and adults with autism spectrum disorder: A systematic review and meta-analysis

This systematic review estimates the prevalence of co-occurring conditions (CCs) in children and adults with autism. A comprehensive search strategy consulting existing guidelines, diagnostic manuals, experts, carers, and autistic people was developed. PubMed and PsycInfo databases from inception to May 2022 were searched. PROSPERO registration: CRD42019132347. Two blind authors screened and extracted the data. Prevalence estimates for different CCs were summarized by using random effects models. Subgroup analyses were performed for age groups (children/adolescents vs adults) and study designs (population/registry-based vs clinical sample-based). Of 19,932 studies, 340 publications with about 590,000 participants were included and meta-analyzed to estimate the prevalence of 38-point prevalence, 27-lifetime, and 3 without distinction between point and lifetime prevalence. Point prevalence of developmental coordination disorder, sleep-wake problem, gastrointestinal problem, ADHD, anxiety disorder, overweight/obesity, feeding and eating disorder, elimination disorder, disruptive behavior, and somatic symptoms and related disorder were the most frequent CCs. Prevalence differed depending on the age group and study design. Knowing specific CCs linked to autism helps professional investigations and interventions for improved outcomes.

Prenatal diagnosis and genetic etiology analysis of talipes equinovarus by chromosomal microarray analysis

BACKGROUND

With the advancement of molecular technology, fetal talipes equinovarus (TE) is believed to be not only associated with chromosome aneuploidy, but also related to chromosomal microdeletion and microduplication. The study aimed to explore the molecular etiology of fetal TE and provide more information for the clinical screening and genetic counseling of TE by Chromosomal Microarray Analysis (CMA).

METHODS

This retrospectively study included 131 fetuses with TE identified by ultrasonography. Conventional karyotyping and SNP array analysis were performed for all the subjects. They were divided into isolated TE group (n = 55) and complex group (n = 76) according to structural anomalies.

RESULTS

Among the total of 131 fetuses, karyotype analysis found 12(9.2%) abnormal results, while SNP array found 27 (20.6%) cases. Trisomy 18 was detected most frequently among abnormal karyotypes. The detection rate of SNP array was significantly higher than that of traditional chromosome karyotype analysis (P < 0.05). SNP array detected 15 (11.5%) cases of submicroscopic abnormalities that karyotype analysis did not find. The most common CNV was the 22q11.2 microdeletion. For both analyses, the overall detection rates were significantly higher in the complex TE group than in the isolated TE group (karyotype: P < 0.05; SNP array: P < 0.05). The incremental yield of chromosomal abnormalities in fetuses with unilateral TE (22.0%) was higher than in fetuses with bilateral TE (19.8%), but this difference was not statistically significant (P > 0.05). Abnormal chromosomes were most frequently detected in fetuses with TE plus cardiovascular system abnormalities.

CONCLUSION

Fetal TE is related to chromosomal microdeletion or microduplication. Prenatal diagnosis is recommended for fetuses with TE, and CMA testing is preferred. CMA can improve the detection rate of chromosomal abnormalities associated with fetal TE, especially in pregnancies with complex TE.

Update from a cohort study for birth defects in Hunan Province, China, 2010-2020

To define the relationship between sex, residence, maternal age, and a broad range of birth defects by conducting a comprehensive cross-analysis based on up-to-date data. Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2010-2020. Prevalences of birth defects (number of cases per 10,000 fetuses (births and deaths at 28 weeks of gestation and beyond)) with 95% confidence intervals (CI) were calculated by sex, residence, maternal age, year, and 23 specific defects. Cross-analysis of sex, residence, and maternal age was conducted, and crude odds ratios (ORs) were calculated to examine the association of each maternal characteristic with birth defects. A total of 1,619,376 fetuses and 30,596 birth defects were identified. The prevalence of birth defects was 188.94/10,000 (95% CI 186.82-191.05). Birth defects were more frequent in males than females (210.46 vs. 163.03/10,000, OR = 1.30, 95% CI 1.27-1.33), in urban areas than in rural areas (223.61 vs. 162.90/10,000, OR = 1.38, 95% CI 1.35-1.41), and in mothers ≥ 35 than mothers 25-29 (206.35 vs. 187.79/10,000, OR = 1.10, 95% CI 1.06-1.14). Cross-analysis showed that the prevalence of birth defects was higher in urban females than in rural males (194.53 vs. 182.25/10,000), the difference in prevalence between males and females was more significant for maternal age < 20 compared to other age groups (OR = 1.64, 95% CI 1.37-1.95), and the prevalence difference between urban and rural areas is more significant for maternal age 25-34 compared to other age groups (OR = 1.49, 95% CI 1.43-1.57). Cleft palates were more frequent in males, and nine specific defects were more frequent in females. Five specific defects were more frequent in rural areas, and eight were more frequent in urban areas. Compared to mothers 25-29, five specific defects were more frequent in mothers < 20, seven specific defects were more frequent in mothers 20-24, two specific defects were more frequent in mothers 30-34, and ten specific defects were more frequent in mothers ≥ 35. Our data indicate that sex, residence, and maternal age differences in the prevalences of birth defects and most specific defects are common. We have found some new epidemiological characteristics of birth defects using cross-analysis, such as residence is the determining factor for the prevalence of birth defects, the difference in prevalence between males and females was more significant for maternal age < 20 compared to other age groups, the prevalence difference between urban and rural areas is more significant for maternal age 25-34 compared to other age groups. And differences in the epidemiological characteristics of some specific defects from previous studies. Future studies should examine mechanisms. Our findings contributed to clinical counseling and advancing research on the risk factors for birth defects.

The global birth prevalence of clubfoot: a systematic review and meta-analysis

Background

Estimates of the birth prevalence of clubfoot in low and middle income settings range from 0.5 to 2 per 1000 births. However, there is currently no estimate of global birth prevalence of clubfoot.

Methods

We conducted a systematic review of studies reporting the birth prevalence of clubfoot across all countries and regions worldwide in the last 10 years. Africa Wide Information, EMBASE, CINAHL, Global Health, LILACS and Medline databases were searched for relevant studies from January 1st 2012 to February 9th 2023. Pooled prevalence estimates were calculated using the inverse variance method, and a random effects model was applied to account for heterogeneity between studies. Quality appraisal was performed using a modified Newcastle-Ottawa Quality Assessment Scale for Cohort studies. This review was registered with PROSPERO, CRD42023398410.

Findings

The search generated 757 studies. Thirty-five studies from 36 countries and five WHO regions were included. The pooled prevalence of clubfoot was 1.18 per 1000 births (95% CI: 1.00-1.36) based on data from 44,818,965 births. The highest prevalence rates were observed in low- and middle-income countries, particularly in the South-East Asia Region (1.80, 95% CI: 1.32-2.28) and the Africa Region (1.31, 95% CI: 0.86-1.77). We estimate that 176,476 (95% CI: 126,126-227,010) children will be born with clubfoot globally each year.

Interpretation

This study provides a comprehensive estimate of the global prevalence of clubfoot and highlights the significant burden of this condition, particularly in low- and middle-income countries. The findings underscore the need for improving access to effective treatment and prevention strategies in resource-limited settings.

Funding

SR received funds from the Global Clubfoot Initiative and the Rhodes Trust.

Epidemiology of birth defects based on a birth defects surveillance system in southwestern China and the associated risk factors

Background

Birth defects (BDs) are associated with many potential risk factors, and its causes are complex.

Objectives

This study aimed to explore the epidemiological characteristics of BDs in Guangxi of China and the associated risk factors of BDs.

Methods

BDs data of perinatal infants (PIs) were obtained from the Guangxi birth defects monitoring network between 2016 and 2020. Univariate Poisson regression was used to calculate the prevalence-rate ratios (PRR) to explore the changing trends of BDs prevalence by year and the correlation between the regarding of characteristics of BDs (including infant gender, maternal age, and quarter) and BDs. Clinical characteristics of PIs with BDs and general characteristics of their mothers were documented, and Spearman correlation analysis was used to explore the potential associated risk factors of BDs.

Results

Between 2016 and 2020, 44,146 PIs with BDs were monitored, with an overall BDs prevalence of 121.71 (95% CI: 120.58-122.84) per 10,000 PIs, showing a significant increase trend (PRR = 1.116, 95% CI: 1.108-1.123), especially the prevalence of congenital heart defects (CHDs) that most significantly increased (PRR = 1.300, 95% CI: 1.283-1.318). The 10 most common BDs were CHDs, polydactyly, congenital talipes equinovarus, other malformation of external ear, syndactyly, hypospadias, cleft lip with cleft palate, cleft lip, hemoglobin Bart's hydrops fetalis syndrome (BHFS), and congenital atresia of the rectum and anus. BDs were positively correlated with pregnant women's age (R = 0.732, P < 0.01) and education level (R = 0.586, P < 0.05) and having pre-gestational diabetes mellitus (PGDM)/gestational diabetes mellitus (GDM) (R = 0.711, P < 0.01), while when the pregnant women had a family history of a dead fetus (R = -0.536, P < 0.05) and a birth of a fetus with BDs (R = -0.528, P < 0.05) were negatively correlated with BDs.

Conclusion

A significant increase in the prevalence of BDs was detected between 2016 and 2020 in Guangxi, especially the prevalence of CHDs that most significantly increased. Older maternal age, higher maternal education level, and having PGDM before pregnancy or GDM in early pregnancy were the risk factors for BDs.

Comparison of fetal and maternal tissue elasticity between euploid and aneuploid pregnancies by shear wave elastography

AIM

B-mode ultrasonography utilized for fetal screening of common trisomies is referred to as a genetic sonogram and includes determining major abnormalities and soft markers such as hypoplastic nasal bone and increased thickness of the nuchal fold. Elastography is a novel ultrasound technique giving information about tissue stiffness used for diagnosing cancer, transplant rejection, and organ fibrosis. This study aimed to determine via shear wave elastography (SWE) whether euploid and aneuploid fetal soft marker tissues vary in stiffness.

METHODS

The participants were all singleton pregnancies between 19 and 23 weeks of gestation; 35 euploid and 14 aneuploid fetus pregnancies were enrolled. Fetal bowel, kidney, liver, nasal bone, nuchal fold, placenta, and myometrium were investigated with SWE using acoustic radiation impulse force. Images were analyzed with a novel software calibrated and written by us using MATLAB. Statistical analysis was completed with the SPSS Program. Shapiro-Wilk normality distribution analysis, Student's t-test, and Mann-Whitney U methods were used.

RESULTS

The mean shear wave speed of fetal nasal bone was significantly lower in aneuploid fetuses. There was no difference between other tissues in mean shear wave velocity.

CONCLUSIONS

Euploid and aneuploid fetuses have different elastic properties of the nasal bone and this may have a role in differentiating aneuploid fetuses noninvasively.

A retrospective single-center analysis of prenatal diagnosis and follow-up of 626 chinese patients with positive non-invasive prenatal screening results

This study explored the diagnostic efficiency of different prenatal diagnostic approaches for women with positive non-invasive prenatal screening (NIPS) results by analyzing their clinical information and pregnancy outcomes. We collected data on 626 NIPS-positive pregnant women from January 2017 to June 2021 and arranged subsequent prenatal diagnostic operations for them after genetic counseling, along with long-term intensive follow-up. A total of 567 women accepted invasive prenatal diagnosis (IPD) (90.58%), and 262 cases were confirmed as true positives for NIPS. The positive predictive values for trisomies 21 (T21), 18 (T18), and 13 (T13); sex chromosome aneuploidies (SCAs); rare autosomal trisomies (RATs); and microdeletion and microduplication syndromes (MMS) were 81.13%, 37.93%, 18.42%, 48.83%, 18.37%, and 41.67%, respectively. Discordant results between NIPS and IPD were observed in 48 cases, with the discordance rate being 8.47%. Additionally, there were 43 cases with discordant results between karyotyping and chromosomal microarray analysis (CMA)/copy number variation sequencing. Additional reporting of RATs and MMS with routine NIPS that only detects T21/T18/T13 and SCAs can yield more accurate diagnoses. However, NIPS cannot be used as a substitute for IPD owing to its high false positive rate and discordance with other diagnostic methods. Therefore, we recommend CMA combined with karyotyping as the preferred method for accurately diagnosing NIPS-positive women.

Congenital anomalies and maternal age: A systematic review and meta-analysis of observational studies

INTRODUCTION

Several studies have reported on the maternal age-associated risks of congenital anomalies. However, there is a paucity of studies with comprehensive review of anomalies. We aimed to quantify the risk of birth defects in children born to middle-aged mothers compared with that in children born to young or older mothers.

MATERIAL AND METHODS

We classified maternal ages into three groups: young (<20 years old), middle (20-34 years old) and older age (≥35 years old). Observational studies that met our age criteria were eligible for inclusion. The articles searched using the Embase and MEDLINE databases were those published from 1989 to January 21, 2021. The Newcastle-Ottawa scale was used to assess the risk of bias. If heterogeneity exceeded 50%, the random effect method was used; otherwise, the fixed-effect method was used. Prospero registration number: CRD42021235229.

RESULTS

We included 15 cohort, 14 case-control and 36 cross-sectional studies. The pooled unadjusted odds ratio (95% CI) of any congenital anomaly was 1.64 (1.40-1.92) and 1.05 (0.95-1.15) in the older and young age groups, respectively (very low quality of evidence). The pooled unadjusted odds ratio of chromosomal anomaly was 5.64 (5.13-6.20) and 0.69 (0.54-0.88) in the older and young age groups, respectively. The pooled unadjusted odds ratio of non-chromosomal anomaly was 1.09 (1.01-1.17) and 1.10 (1.01-1.21) in the older and young age groups, respectively (very low quality of evidence). The incidence of abdominal wall defects was increased in children of women in the young maternal age group.

CONCLUSIONS

We identified that very low quality evidence suggests that women in the older maternal age group had increased odds of having children with congenital anomalies compared with those in the 20-34 year age group. There was no increase in odds of children with congenital anomalies in women of <20 year age group except for abdominal defects compared with those in the 20-34 year age group. The results stem from very low quality evidence with no adjustment of confounders.

Exosomal miR-486-5p derived from human placental microvascular endothelial cells regulates proliferation and invasion of trophoblasts via targeting IGF1

Preeclampsia (PE) is a serious complication of pregnancy. Exosomes are known to be upregulated in PE. In this study, we sought to investigate the effect of miR-486-5p from human placental microvascular endothelial cells, on the function of trophoblast cells. To investigate the function of human placental microvascular endothelial cell (HPVEC)-derived exosomes on trophoblast cells, HPVECs were treated with hypoxia/reoxygenation (H/R). The separation efficiency of exosomes was determined by transmission electron microscopy, nanosight and Western blot. Cell Counting Kit-8, EdU staining, wound-healing, and transwell assay were performed to detect the effect of exosomally transferred miR-486-5p inhibitor on proliferation, migration and invasion of trophoblast cells. MiRDB and dual-luciferase report assay were used to find the target of miR-486-5p. Our data revealed that miR-486-5p was significantly upregulated in H/R-treated HPVEC-Exo, and miR-486-5p was enriched in HPVEC-Exo. miR-486-5p inhibitor carried by HPVEC-Exo significantly inhibited the proliferation, migration and invasion of trophoblast cells. Insulin-like growth factor 1 (IGF1) was found to be the target of miR-486-5p, and IGF1 overexpression notably reversed the effect of miR-486-5p inhibitor from HPVEC-Exo on trophoblast cell function. In summary, H/R-treated HPVEC-derived exosomally expressing miR-486-5p inhibitor significantly inhibited the proliferation, migration and invasion of trophoblast cells via downregulation of IGF1. The findings from the present study may be useful in the development of treatments for PE.