VII. Genetic Disorders A. Turner’s Syndrome – females w/ only 1 X chr. (XO) Nondisjunction 1 out of 3,000 infertile Short stature Webbed neck

B. Klinefelter’s Syndrome – males w/ an extra sex chromo. (XXY) - Nondisjunction - 1 out of 2,000 births - infertile - lower IQ

C. Down’s Syndrome - (Trisomy 21) – extra 21 st chromo. Nondisjunction mental retardation, muscle weakness, heart defects, short stature 1 in 1,000 when mom is age 15-34, 1 in 400 at age 35

D. Cri du chat - deletion of a segment of DNA in chromo 5. - affects development of larynx - cry sounds like a cat - mental retardation - 1 in 50,000

E. Cystic fibrosis – excess mucus clogs lungs & digestive system autosomal recessive 30,000 people in US Average age 37

F. Sickle Cell Anemia – red blood cells are distorted sickle shape; unable to bind oxygen properly autosomal recessive 1 in 5,000 (1 in 500)

G. Huntington’s Disease – deterioration of brain tissue in middle age autosomal dominant yrs of life after diagnosis

H. Edward’s syndrome (Trisomy 18 )- extra 18 th chromosome Most babies die at death < 10% will live up to 1 year