LG3.10 Genetics of Connective Tissue Disorders – Dr. Olson Flashcards
What is allelic heterogeneity?
One phenotype produced by different mutations at the same locus.
What is an example of allelic heterogeneity?
Cystic fibrosis
What is locus heterogeneity?
One phenotype produced by different mutations at different loci.
What is heterogeneity?
Is a phenomenon in which a single phenotype or genetic disorder may be caused by any one of a multiple number of alleles or non-allele.
What is a dominant negative mutation?
Abnormal function that interferes with nomad allele
What is pleitoropy?
Occurs when one gene influences multiple, seemingly unrelated phenotypic traits, an example being phenylketonuria, which is a human disease that affects multiple systems but is caused by one gene defect.
What is collagen made by?
Fibroblasts.
What is Ehlers-Danlos syndrome?
- Class of 10 disorders with joint flexibility problems
- Loose joints
- Strechy skin
What is Epidermolysis Bullosa?
-Skin blisters and tearing
What are the three types of Epidermolysis Bullosa?
- EB simplex
- Junctional EB
- Dystrophic EB
What is EB simplex?
Autosomal dominant, keratin mutation
What is junctional EB?
Autosomal recessive, laminin and collagen in basement membrane of epithelia.
What is Dystrophic EB?
COL7A1, dominant and recessive
What is Marfan syndrome?
- Long, tall, fragile
- Fibrillin
What gene is suspected in Marfan syndrome?
FBN1 gene is also part of a cell signaling pathway, increasing TGF-B signaling
What is the major issue caused by Marfan syndrome?
Weakened heart, valves, lungs, and aorta.
What is osteogenesis imperfecta?
-Brittle bone disease
What type of mutation normally occurs in osteogenesis imperfect?
Type 1 collagen mutation
What specific location of a coding sequence on a chromosome is known as a? A) An allele B) A locus C) A chiasma D) A genotype E) A phenotype
A) A locus
I am a carrier of an autosomal recessive disease, like Tay’Sach’s, but am otherwise normal. As a carrier I do not have the disease, but carry an allele that may give it to my offspring. Am I wild Type?
YES!
A patient with a muscular dystrophy is producing a dystrophin gene product that is missing 35 amino acids on its carboxyl end? Which mutation is the set candidate?
Nonsense Mutation
