Down syndrome is a genetic disorder caused by the presence of an extra chromosome 21. It occurs in about 1 in 800 births, with 88% of cases arising from the mother's chromosome 21. Individuals with Down syndrome often experience hearing loss in at least one ear and congenital heart defects.

1. DOWN SYNDROME
RITHIKA. R. S | II M. Sc. Bioinformatics
 Treatment is basically symptomatic and complete
recovery is not possible.
• About 1 in 800 risk overall births. 3,40,000 cases in USA
• 88% of cases arise from mother’s chromosome 21; 8% from
father’s chromosome & 2% from mitotic errors after fusion.
• 66-88% - has hearing loss in at least 1 ear. 40-50% - has
congenital heart defects.