Down Syndrome
DEFINITION
The condition wherein the Child’s physical and mental development is delayeddue to presence of extra genes is known as Down Syndrome.
It is a congenital disorder arising from achromosome defect, causingimpairment and physical abnormalities including short stature and broad facialprofile.
CAUSES
All cells in the body contain genes that aregrouped along chromosomes in the cell nucleus. There are normally 46chromosomes in each cell – 23 inherited from the mother and 23 from the father.
The most common form of down syndrome is calledtrisomy 21. This is a condition where in people have 47 chromosomes in eachcell instead of 46. An error in cell division called nondisjunction causestrisomy 21.
PATHOPHYSIOLOGY
Most cases of Down Syndrome are not inherited whenthe condition is caused by trisomy 21, the chromosomal abnormality occurs as arandom event during the formation of reproductive cells in a parent. An errorin cell division called nondisjunction results in a reproductive cell with anabnormal number of chromosomes.