Down syndrome among primiparae at older maternal age: A test of the relaxed filter hypothesis

Chromosomal and cellular therapeutic approaches for Down syndrome: A research update

In individuals with Down syndrome (DS), an additional HSA21 chromosome copy leads to the overexpression of a myriad of HSA21 genes, disrupting the transcription of the entire genome. This dysregulation in transcription and post-transcriptional modifications contributes to abnormal phenotypes across nearly all tissues and organs in DS individuals. The array of severe clinical symptoms associated with trisomy 21 poses a considerable challenge in the quest for a cure for DS. Fortunately, a wealth of research suggests that chromosome therapy, hinging on cutting-edge genome editing technologies, can potentially eliminate the extra copy of the human chromosome 21. Genome editing tools have demonstrated their efficacy in restoring trisomy to a normal diploid state in vitro DS cell models. Furthermore, we delve into the noteworthy findings in cellular therapy for DS, with recent studies showcasing the increasing feasibility of strategies involving stem cells and CAR T-cells to address corresponding clinical phenotypes.

Risk factors characterisation for CHD: a case-control study in Bogota and Cali, Colombia, 2002-2020

OBJECTIVE

CHDs correspond to 28% of all congenital anomalies, being the leading cause of infant mortality in the first year of life. Thus, it is essential to explore risk factors for CHDs presentation, allowing the detection of probable cases within a population.

METHODS

We identified newborns with CHDs within a cohort from the Program for the Prevention and Monitoring of Congenital Defects in Bogota and Cali, 2002-2020. Cases were classified as isolated, complex isolated, polymalformed, and syndromic. Variables were analysed by comparing case and control averages with Student's t test using a 95% confidence level.

RESULTS

Prevalence obtained was 19.36 per 10 000 live births; non-specified CHD, ventricular septal defect, and atrial septal defect were the most prevalent. As risk factors were found: paternal and maternal age above 45 years, pregestational diabetes, mother's body mass index above 25, low educational level, and socio-economic status. As protective factors: folic acid consumption within the first trimester and pregestational period.

CONCLUSION

Different risk and protective factors associated with the presentation of CHDs have been described. We consider that public health strategies should be aimed to reduce risk factors exposure. Also, improving diagnosis and prognosis by having a close monitoring on high-risk patients.

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.