11-4 Human Genetic Disorders
Autosome - any chromosome other than the X & Y
(humans have 22 pairs of autosomes + 1 pair of sex chromosomes)
Patterns of Inheritance
Autosomal Recessive
- Most affected children have unaffected parents
- Heterozygotes (carriers) are unaffected
Tay - Sachs Disease
- More common among Jewish populations
- Young children begin showing signs of slowed development
- Severe impairment and death
Cystic Fibrosis
- More common in European-descended people
- Mucus in respiratory tract, difficulty breathing
- extreme salty sweat
- Mucus may cause secondary infections
Phenylketonuria (PKU)
- Lack enzyme for normal metabolism
- Phenylalanine builds up and causes brain damage
- Newborns are routinely tested
- Changes in diet lead to normal life
Sickle Cell Disease
- More common in Africans (African-Americans)
- Causes blood to be sickle shaped
- Affects oxygen flow to organs, causing weakness, pain, anemia, etc
- Heterozygotes are resistant to malaria
Autosomal Dominant
- Affected children usually have an affected parent
- Heterozygotes are effected
- Two heterozygotes (Hh x Hh) can produce a normal (hh) child
Neurofibromatosis
- Tumors form under skin and
- Can cause skeletal deformities, blindness
Huntington Disease
- Neurological disorder, progressive degeneration of the brain
- Symptoms appear later in life
Achondroplasia
- Common form of Dwarfism
- Short arms and legs, normal torso
- Homozygotes (AA) do not survive
