Autosomal Dominance Inheritance

What’s an Autosome? Autosome: Non sex chromosome – Ex: Autosomal disorders: gene for the disease is found on chromosomes 1-22 Autosomal Recessive Inheritance – Must inherit two copies of the disorder to be affected – Healthy is dominant (HH or Hh) – Disease is recessive (hh) – Ex: Cystic fibrosis, PKU, Albinism, Sickle cell anemia Autosomal Dominance Inheritance – Only need to inherit one copy of the disorder to be affected – Disease is dominant (HH or Hh) – Healthy is recessive (hh) – Ex: Familial hypercholesterolemia (also called FH), Huntington’s disease, Neurofibromatosis

Autosomal Dominance Inheritance Disease is dominant (HH or Hh) – Homozygous dominant: early death and don’t survive to reproduce – Heterozygous live into adulthood Healthy is recessive (hh) ex: Paul has familial hypercholesterolemia and Stacy is healthy. The two have 3 children. After testing, the middle child is the only healthy child. Key H = FH disease h= healthy disease healthy PaulStacy Hh hh

Autosomal Dominance Inheritance Huntington’s disease is a dominant disorder found on chromosome 4. Betty and Marcus met at a support clinic they have been attending to help them cope with the knowledge of their illness with Huntington’s disease. They would like to know the risk of having a healthy child, now that Betty is pregnant. Key H = Huntington’s disease h = healthy Disease (severe) disease diseasehealthy ? MarcusBetty Hh

Video about Huntington's disease Autosomal dominant disorder Brain cells start to die in late 30’s Causes uncontrollable muscle jerking Death usually in 40’s-50’s No treatments Click if YouTube video doesn’t work

review 1)How are autosomal dominant disorders different from autosomal recessive disorders? 2)What are the possible genotypes of someone with an autosomal dominant disorder? 3)In all likelihood, what is the genotype of an adult with an autosomal dominant disorder? 4)Complete a pedigree from the following story: Jerome is concerned about Huntington’s disease (HD) since his father recently passed away due from the disorder. After a gene test, he is found to not have the HD gene. He marries Raquel and they are now preparing for their first child. a)What is the likelihood of the child having HD if Raquel is healthy? b)What is the likelihood of the child having HD if Raquel has HD?