Understanding the steps of meiosis is essential to learning how errors occur. Researchers' initial understanding of meiosis was based upon careful observations of chromosome behavior using light ...

A century after Down syndrome was first described, scientists discovered that the root cause of this disorder is a condition called trisomy 21. What strides in research have been made since then?

During meiosis II, each haploid cell divides its ... The recurrence risk with trisomy is 1% to 2% or the maternal age risk, whichever is greater. [2] There is a recurrence risk of 5% to 10% ...

Recognition of the clinical features of Trisomy 13 syndrome, a common autosomal trisomy, provides the basis for diagnostic testing and counseling of families. This article provides a systematic ...