<p>The overall goal of the project is to identify genetic risk factors associated with chromosome 21 nondisjunction in the oocyte. The dataset derives from multi-site collection of live birth probands with Down syndrome due to standard trisomy 21 (T21) and their biological parents. The type of nondisjunction error (NDJ)(maternal or paternal) in all cases has been determined to be maternal in origin based on the chromosome 21 variants contributed from parent to proband. The Center of Inherited Disease with support from NICHD has conducted genome-wide genotyping using the Illuminia Human OmniExpress Plus Exome array on approximately 800 women who have been identified through their offspring with DS and have been characterized as having a maternal meiois I (MI) or meiosis II (MII) nondisjunction error. Genotypes from biological fathers of the offspring with DS can be used with the data on mothers to better define the type of nondisjunction error (MI or MII) and to refine the chromosome 21 recombination profile. We provide the type of nondisjunction error, knowing that this will be updated based on the new panel. We do not provide the recombination profile, as this can be best defined using the new comprehensive set of SNPs in the OmniExpress panel.</p>

Trisomy 21 Nondisjunction (T21NDJ)

New Insights into Human Nondisjunction of Chromosome 21 in Oocytes

Altered patterns of multiple recombinant events are associated with nondisjunction of chromosome 21

Evidence for dysregulation of genome-wide recombination in oocytes with nondisjoined chromosomes 21.