In trisomy 22 disorder, chromosome 22 appears three times instead of twice in some cells, according to the National Organization for Rare Disorders. The degree of the patient's impairment depends on how many cells have three copies of the chromosome.
People with trisomy 22 often suffer from mental retardation, claims the National Organization for Rare Disorders. They do not develop at the same rate as other children, and the two halves of their bodies may be different in size and shape. Many are deaf in one ear. Other problems include abnormalities in the heart, including the aorta, an unusual number of birthmarks and deformed nails. Females with the disorder often do not achieve puberty or achieve puberty later than usual.