Jerome Lejeune in France and Patricia Jacobs in the United States were able to identify a supernumerary copy of chromosome 21 in karyotypes prepared from DS patients (Figure 2). Trisomy 21 is now ...

CC has full Trisomy 18, also known as Edwards syndrome; an extra copy of the 18th chromosome in each of her body’s cells ...

Note the potential formation of monosomy or trisomy. Once fertilization occurs, the gamete with 24 chromosomes forms a zygote with 47 chromosomes (a trisomy with an extra copy of 1 chromosome).

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 ...

People who are born female usually have two X chromosomes. Triple X syndrome (also called trisomy X syndrome, XXX syndrome, or 47,XXX) is a rare genetic condition where females inherit an extra X ...

Scientists have found six cases of Down syndrome and one case of the very rare Edwards syndrome in the DNA of ancient infants, according to a study published in the journal Nature Communications. In a ...

Aneuploidy occurs when there are either too many or too few chromosomes in cells. Down syndrome, for example, is caused by a trisomy—three copies instead of two—of chromosome 21. Amniocentesis and ...