Autosomal Dominant Disorder explanation and Marfans Flashcards
Single gene defects follow the mendelian pattern of inheratance, therefor they are sometimes called
mendelian disorders
Are autosomal dominant disorders usually detected early or late in life
late
What is the percentage of passing on a dominant genetic disorder
50%
Is it possible for an unaffected person to pass the disorder to its offspring
yes, if that person inheirted the mutant gene but the trait has reduced penetrance then the disorder may never be expressed however they can still pass it on
How is penetrance expressed?
through mathematics i.e. 50% chance
What is marfans prevelance
1 per 20000
What percentage of marfan cases are familial
75%
What chromosome does Marfans affect
affects a gene of chromosome 15 that codes for fibrillin
Why is fibrillin important
it is an essential part of the ECM that is involved with scaffolding for elastin rish tissues like heart valves and blood vessels because it contributes to the structure
What are the three systems marfans can effect
ocular
cardiovascular
skeletal
What are the symptoms of marfans on the ocular system
myopia
lens delocation due to weak suspensory ligaments
retinal detachment
What are the symptoms of marfans on the skeletal sys
long thin bodies long extremities long fingers called arachnodactyly hyperextensible joints spinal deformities like scoliosis and kyphosis pectus excavatum pectus carinatum (pigeon chest)
What are the symptoms of marfans on the cardiovascular sys
mitral valve prolapse
dialation of aortic valve ring
weakness of arteries like the aorta and others
In pregnant women affected by marfans, what risk is increased
aortic dissection
Which system most commonly affected
the skeletal system
