According to the University of Illinois at Chicago, the most common result of autosomal nondisjunction is Down syndrome. About 5000 individuals are born with Down syndrome each year.
Nondisjunction is the failure of chromosomes to disjoin, or separate, and move away to opposite poles. During reproduction, if a zygote receives a third copy of a chromosome from the gamete, it becomes trisomic. This leads to autosomal nondisjunction.
In most of these cases, the zygote does not survive. However, Down syndrome, also known as trisomy 21, is an exception. Nondisjunction is the cause of ninety-five percent of all Down syndrome cases.
Features of Down syndrome include short, stocky arms, slanted eyes, small ears and a short, wide neck according to WebMD.