Genetic Disorders Flashcards
Autosomal dominant/recesive chance for inheritance
dominant- 50% chance of inheritance if the gene is present in one parent
recessive- 25% chance of inheritance if both parents have it
What are 3 examples of autosomal chromosomal diseases
Downs (trisomy 21-extra 21st chromosome)
Klinefelter (XXY- extra X in tall, thin sterile males)
Turners syndrome (XO- missing x in short females, web neck etc)
What are some autosomal dominant diseases(4)
Marfans (Genetic defect in fibrilin-1- lens dislocation, mitral valve prolapse, aortic aneurynm)
Ehhlers-danlos
Osteogenesis imperfecta (defective collagen synthesis, blue sclera)
Adult polycystic disease
what are the glycogen storage diseases (3)
Von Gierke- glu 6 phosphatase def
McArdle- mm phosphorylase def
Pompe- maltase defeciency (affects heart)
What are the lysosomal storage disorders(+mc)
Tay sachs - accumulation in brain (red macula/severe retardation)
Gaucher- glucocerebrosides accumulate in liver/spleen (M/C)
Niemann Pick- Sphingomyelin accumulation in liver/brain
What are the amino acid disorders (2)
Phenylketonuria- accumulation of phenylalaninee due to lack of PA hydroxylase (Guthrie test pos)
Alkaptonuria- def in homogentistic acid (urine turns black on standing)
what is cystic fibrosis
Autosomal recessive condition causing defective Chl transport
-impaired mucocilary action, recurrent infections, salty sweat
What is sickle cell disease and what does it cause
recessive gene
-valine replaces glutamine at pos 6 of hemoglobin
-causes microvascular occlusion triggers by hypoxia, acidosis, fever
-protects from Plamodium falciparum type of malaria
What is thalasemai and two types
defect in either the a or b globe changes of hemoglobin A
A thalassemia mc in south east asia/ west africa
B thalassemia mc in Americans of greek/italian descent
=presents w anemia/fatugue
what are the recessive sex lined disorders
Duchenne mm dystrophy
Beckers mm dystrophy
Hemophillia A or B
Lesch-Nyhan syndrome
What is duchenne mm dystrophy and s/s
Total absence of dystrophin
-progressive mm weakness
ss= pseudohypertrophic calf mm, Gowers sign
What is beckers mm dystrophy
milder form of duchesses with decrease levels of dystrophin
What is hemophilia A/B due to
lack of factor VIII (A) or Factor IX(B)
-prolonged bleeding
What is LEsch-Nygan syndrome (+what is it due to)
Lack of HGPRT for purine metabolism
-gout in children
-congenital pain insensitivity
What is a dominant sex linked disorder
Vit D resistent rickets
(rickets that does not respond to Vit D therapy)
