Genetic Disorders
Genetic Disorders: A genetic disorder results from an inherited
disruption in an organism’s DNA Can be a change in the number of
chromosomes and deletion or duplication of entire chromosome or part of chromosome
Disorders can be linked to a change in a single specific gene
Cystic Fibrosis (CF) Recessive disorder 1 in 2500 births 5% of pop. are carriers
Phenylketonuria (PKU) Recessive disorder 1 in 10,000 births Inheritance of genetic
mutation Leads to mental
retardation
and epilepsy if not treated
Down Syndrome Faulty gamete cell division Small % inherit
chromosomal
defect from mother or father
Excess of chromosome 21 Cause mental retardation,
hearing loss, heart defects
Tay Sachs Disease 2 Tay sach carriers
have 1 in 4 chance of passing on disease
Fatal inherited disease
Affects buildup of fatty substances in brain and nerve cells
Sickle Cell Anemia Heredity disease 1 in 12 African
Americans carry sickle cell traits
Red blood cells become rigid and curved
Can cause anemia
Hemophilia Bleeding and clotting
disorder Sex-linked disorder –
about 1 in 4,000 males are born with disorder each year
Have mutation in Factor VIII gene
Albinism Little or no pigment in
their eyes, skin, and hair
Affects about 1 in 17,000 births each year
Can occur in humans and animals
Dwarfism Usually refers to primary
bone disorder—bones do not grow and develop properly
Affects 1 in 40,000 children born each year
Commonly causes short limbs and bowed legs
Progeria Rare, fatal genetic
disorder Name comes from greek
meaning “prematurely old” Mutation in gene called
LMNA Children usually die of
heart disease by age 8-13 100 cases since 1886
Osteogenesis Imperfecta Literally means “bone that
is imperfectly made from the beginning of life”
Also called “brittle bone disease”
Most cases caused by dominant genetic defect or spontaneous mutation
1 in 20,000 births
Cleft Lip & Palate 1 in 700 children will
be born with a cleft-related birth defect
Most are boys If a person has a cleft
defect, there is a 50% possibility of passing gene to an offspring
Clubfoot One or both feet can
be affected Affects 1 out of every
100 births Risk factors: family
history of disorder and being male