Down syndrome results from extra chromosome 21 during cell division. Named after English physician John Langdon Down. Most common genetic cause of intellectual disabilities in children. Causes lifelong intellectual disability and developmental delays
Down syndrome is a genetic condition caused by an extra chromosome 21. Named after John Langdon Down, who first described it in 1860s. Affects 1 in 700 babies in U.S., making it most common chromosomal condition
Down syndrome affects about one in 700 newborns. Caused by extra chromosome 21 in cells. Three types exist: trisomy 21 (95%), translocation (3%), and mosaic (2%)
Down syndrome results from extra genetic material on chromosome 21. Named after British physician John Langdon Down, who first described it in 1866. Occurs in about 1 in 700-1,100 live births
Chromosome 21 is the smallest human autosome and chromosome. Contains 46.7 million base pairs, representing 1.5% of total DNA. Most people have two copies, three copies cause Down syndrome. Sequenced in 2000, second human chromosome after chromosome 22
Autosomes are non-sex chromosomes in diploid cells. Human genome contains 22 pairs of autosomes and one allosome pair. Autosome pairs have same morphology unlike allosomal pairs. DNA in autosomes is called atDNA or auDNA