Chromosomal disorder is an abnormality in numbers and/or structure of chromosomes.

Normal chromosome
normal female
karyotype 46,XX
normal male
karyotype 46,XY

       The most common congenital malformations and frequent cause of mental retardation is "Down Syndrome".
       The overall incidence is 1 in 600 and rises significantly for pregnant women age 35 and over.
BACK