Genetic aetiology of Down syndrome birth: novel variants of maternal DNMT3B and RFC1 genes increase risk of meiosis II nondisjunction in the oocyte.

The aim of the present work was to explore the intriguing association of maternal folate regulator gene polymorphisms and mutations with the incidence of chromosome 21 nondisjunction and Down syndrome birth. We tested polymorphisms/mutations of DNMT3B and RFC1 genes for their association with meiotic errors in oocyte among the 1215 Down syndrome child-bearing women and 900 controls. We observed that 23 out of 31 variants of DNMT3B and RFC1 exhibited an association with meiosis II nondisjunction in maternal age-independent manner.

Differences in clinical presentation, severity, and treatment of COVID-19 among individuals with Down syndrome from India and high-income countries: Data from the Trisomy 21 Research Society survey.

Background: People with Down syndrome (DS) are one of the highest risk groups for mortality associated with COVID-19, but outcomes may differ across countries due to different co-morbidity profiles, exposures, and societal practices, which could have implications for disease management. This study is designed to identify differences in clinical presentation, severity, and treatment of COVID-19 between India and several high-income countries (HICs).

Methods: We used data from an international survey to examine the differences in disease manifestation and management for COVID-19 patients with DS from India vs HIC.

Understanding etiology of chromosome 21 nondisjunction from gene × environment models.

Maternal risk factors and their interactions with each other that associate chromosome 21 nondisjunction are intriguing and need incisive study to be resolved. We determined recombination profile of nondisjoined chromosome 21 and maternal genotypes for four selected polymorphic variants from the folate regulators genes stratifying the women according to the origin of segregation error and age at conception. We conducted association study for genotype and maternal addiction to smokeless chewing tobacco, usually chopped tobacco leaves or paste of tobacco leaves with the incidence of Down syndrome birth.

Evaluation of potency of the selected bioactive molecules from Indian medicinal plants with M of SARS-CoV-2 through in silico analysis.

Background: The recent outbreak of the novel SARS-CoV-2 across the globe and the absence of specific drug against this virus lead the scientific community to look into some alternative indigenous treatments. India as a hub of Ayurvedic and medicinal plants can shed light on its treatment using specific active bio-molecules from these plants.

Objectives: Keeping our herbal resources in mind, we were interested to inquire whether some phytochemicals from Indian spices and medicinal plants can be used as alternative therapeutic agents in contrast to synthetic drugs.

The etiology of Down syndrome: Maternal MCM9 polymorphisms increase risk of reduced recombination and nondisjunction of chromosome 21 during meiosis I within oocyte.

Altered patterns of recombination on 21q have long been associated with the nondisjunction chromosome 21 within oocytes and the increased risk of having a child with Down syndrome. Unfortunately the genetic etiology of these altered patterns of recombination have yet to be elucidated. We for the first time genotyped the gene MCM9, a candidate gene for recombination regulation and DNA repair in mothers with or without children with Down syndrome.

Risk of Down syndrome birth: Consanguineous marriage is associated with maternal meiosis-II nondisjunction at younger age and without any detectable recombination error.

Consanguineous marriage was examined as a risk factor for Down syndrome birth. We genotyped Down syndrome family trios using short tandem repeat markers on 21q-to interpret the parental and meiotic stage of origin of errors as well as to record recombination profile along long arm of chromosome 21. We then compared nonconsanguineous (N = 811) group with-the consanguineous (N =157) marriages.