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22 Cards in this Set
- Front
- Back
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Common cause of familial hypertrophic cardiomyopathy
Inheritance pattern? |
mutation in gene for the Beta myosin heavy chain (MYH7).
Autosomal Dominant |
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Fxn of the MYH7 (beta myosin heavy chain)
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part of the myosin motor unit (contractile / sacromere unit)
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Why does a mutation in the MYH7 cause hypertrophy?
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heart works harder than before due to mutation of MHY7 (beta myosin heavy chain)
Anchoring proteins are effected |
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Achondroplasia Mutated Gene
Nucleotide AA |
Mutation in the FGFR3
nucleotide: Guanine 1138 Adenine AA: Glycine 380 Arginine |
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What type of mutation is FGFR3?
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AD with 100% penetrance
80% are new mutations |
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What happens to a homozygous individual for the mutated achondroplasia gene?
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Dies before birth
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What is the cellular fxn of FGF?
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FGFs in conjunction with FGFRs alter transcription
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How does FGFR3 affect bone growth?
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negatively regulates bone growth. Mutation in the G380R results in consitutive activation of the FGFR which is a gain of function mutation
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What kind of mutation in collagen type I is usually lethal?
What is the name for this kind of osteogenesis imperfecta? |
Glycine mutation is lethal
needed to fold the collagen into a triple helix. The name is Type II OI – GLY Substitutions |
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Mutations in what part of gene are the most severe?
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Glycine mutations are the worst since it affects folding.
C-terminus are worst then N terminus |
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What type of osteogensis imperfecti presents with blue sclera?
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Type 1 and Type 2
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A patient with large joint hypermobility, cigarette paper scars and skin hyperextensibility would have what kind of EDS?
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EDS Type 1 or 2
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What causes classical EDS?
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Classical EDS = EDS type 1 and 2
mutation in type V collagen or type 1 collagen |
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What is normally seen in patients with EDS?
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Hyperextensibility
Hyperjointmobility Conntective tissue fragility |
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What is the inheritance pattern?
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Autosomal dominant (structural protein)
Autosomal recessive (enzyme) |
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What kind of EDS is most often lethal form of EDS?
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VEDS (vascular ED) type IV
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Why is type IV the most lethal form of EDS?
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leads to arterial rupture or spontaneous rupture of colon
No hyper mobility & flexibility |
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What is one kind of EDS that is a result of a defect in enzyme that processes collagen?
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EDS type VI ; defects in the lysl hydroxylase gene
add OH to lysine side chain where it usually has an Amine group |
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What causes EDS VIII?
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defects in conversion of type I procollagen to collagen
due to deletion in exon 6 or defects in the converting enzyme pro-collagen N-protease. |
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What two problems occur with marfan syndrome?
Why does this happen? |
MV prolapse
aortic aneurysm fibrillin is altered and is involved with elasticity of CT |
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Most common cause of mutation in marfan syndrome?
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cystine substitutions in FBN1 = severe
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How are the mutations causing Marfan syndrome described? Why are they called this?
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the cysteine mutations are called dominant negative mutations b/c if one gene is present it will interfere witht he good gene product and messes them both up
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