Genetics

Color Blindness w Occurs more frequently in men w sex-linked (X) w affects light receptors in the eye red/green complete

Muscular Dystrophy w Progressive muscle weakness/loss of muscle tissue w Sex - linked w X chromosome w usually begins in early childhood

Cystic Fibrosis w Inherit 2 “CF” genes (recessive) w autosomal disorder w mucus builds up in lungs w 2,500 babies are born with cystic fibrosis in the U.S. each year. w More than 10 million Americans carry the cystic fibrosis gene but don't know it.

Turner Syndrome w A single X chromosome w 1/2500 births w sex organs do not mature w may be shorter than average w puffy hands/feet w neck skin w sterile

TURNER’S SYNDROME

Klinefelter Syndrome w XXY w 1/1000 births w small testes w sterile (cant produce sperm) w feminine body characteristics w taller than average

XYY

Down Syndrome w Trisomy 21 w broad, flat face w upslanted eyes w mental retardation w 1/700 births in U.S. w The older you are the greater your risk!

DOWN SYNDROME

Fragile X Syndrome w Abnormal X chromosome w mental retardation w 1/2500 males w 1/1500 females

PATAU SYNDROME TRISOMY 13

PATAU

Dwarfism w Average size trunk with short arms and legs typical

BALDNESS w Sex-Influenced traits. w More common in men than women. w Not exactly sure where this trait resides? w Men get it if homozygous recessive bb or heterozygous Bb! Women only get it if they are homozygous recessive bb.

HUNTINGTON DISEASE w Dominant Trait. w Shows up in the thirties and forties, damage to nervous system begins. w Leads to mental retardation and loss of muscle control w Located on the 4th chromosome

SICKLE CELL ANEMIA w A disorder where the red blood cells are in the shape of a sickle. w Co-dominant disorder w heterozygous=carriers w Mostly found in people with african heritage. Located on chromosome 11, hemoglobin gene.

w African Americans 1/500 babies born w Reason? Malaria, SCA is partially resistant.

HEMOPHILIA w Sex-linked disorder w Recessive allele w bleeder’s disease w Clotting factor is missing. w 1:10,000 males w 1:100,000,000 females w treatment-injecting clotting factors

SPINA BIFIDA w When vertebrae in your spinal cord fail to develop and leaves a space causing damage to the nervous system

Cri Du Chat w 1: 50,000 w deletion on chromosome 5 w abnormal larynx development w cry of the cat w Low birth weight w Respiratory problems

Tay Sachs w Fatty material build up in nerve cells w Caused by a abnormal enzyme w The child becomes blind, deaf, and unable to swallow. Muscles begin to atrophy and paralysis sets in. Other neurological symptoms include dementia, seizures, and an increased startle reflex to noise w Children die within the first years of life w Recessive disorder.

Edwards Syndrome w This syndrome produces severe mental retardation & a highly characteristic patter of malformations such as elongated skull, very narrow pelvis, rocker bottom feet & a grasping of the 2 central fingers by the thumb & little finger. In addition, the ears are often low set & the mouth & teeth are small. Nearly all babies born with this condition die in early infancy. Frequency is 1/5,000 live births.

Meiosis w