Down syndrome is caused by the presence of a third chromosome 21
A trisomy. A monosomy is when there is only one of a chromosome. A trisomy is when there are three of a chromosome. In Klinefelter's syndrome, there are three sex chromosomes.
Trisomy 21 is down's syndrome, which is an extra copy of chromosome 21
Patau's Syndrome Trisomy 13 Syndrome Trisomy D Syndrome Trisomie 13 Trisomee Trisome Trisomic Chromosomal Abnormalities, Chromosome Anomalies, Disorder Fetal Aneuploidy
Edwards' syndrome
Trisomy 18 syndrome
Down's Syndrome is an example of trisomy, where there is an extra copy of chromosome 21. Turner Syndrome and Klinefelter's Syndrome are not trisomies; Turner Syndrome is a monosomy of the X chromosome, and Klinefelter's Syndrome is a trisomy of the sex chromosomes (XXY).
Down syndrome is trisomy 21
Trisomy 21
Edward's syndrome
The scientific name for Down syndrome is Trisomy 21, referring to the presence of an extra copy of chromosome 21 in each cell.
Well Down Syndrome is sometimes called Up Syndrome because most kids with Down Syndrome are very happy.Trisomy 21