Deck 1 Flashcards
What gene is associated with increased risk for DM Type 1?
HLA2 genes involved in antigen presentation.
What genes are linked to early-onset alzheimer’s?
APP, Presenilin-1, Presenilin-2
What genes are linked to late-onset alzheimer’s?
APEO, EP2 / EP4 (EP2 is protective)
What is the inheritance pattern of osteogenesis imperfect?
autosomal dominant negative
What causes achondroplasia?
gain of function mutation in FGFR3
What causes fragile X
More than 200 CCG repeats on X chromosome
What causes huntington’s?
Many copies of CAG repeat
What is the inheritance pattern of hereditary retinoblastoma?
autosomal dominant (autosomal recessive at the cellular level)
What is the inheritance pattern of muscular dystrophy?
X-linked recessive
What is the inheritance pattern of achondroplasia?
autosomal dominant (gain of function mutation)
What is the inheritance pattern of Alpha-1-antitrypsin deficiency?
autosomal recessive (increased risk of lung cancer and chronic liver problems)
What is the inheritance pattern of myotonic dystrophy?
autosomal dominant (Triple repeat expansion)
What is the inheritance pattern of osteogenesis imperfecta?
dominant negative
What is a method of treating urea cycle disorders?
sodium benzoate with glycine shunts NH3 to hippurate which can be excreted in the urine.. Can also use phenylacetate with glutamine.
What’s a method of treating beta thalassemia?
butyrate, helps rescue by up regulating HbF synthesis.
What is Leber congenital amaurosis and how do you treat it?
congenital degenerative vision problem. Treat with aden-associated virus gene therapy. AR
What is Prader-Willi syndrome and how is it inherited?
Low stature, intellectual disability, low muscle town - due to uniparental maternal disomy for a portion of chromosome 15.
What is Angelman syndrome and how is it inherited?
neurogenetic disorder involving severe intellectual disability, seizures, sleep disturbances - due to uniparental paternal disomy, mirror image of prader-willi
What do cytogenomic arrays detect?
copy number changes (won’t catch a paracentric inversion)
Paracentric vs. pericentric - which inversion involves the centromere?
pericentric.
What is the most common form of genetic hemoglobinopathy in individuals of italian ancestry?
beta thalassemia
What is presymptomatic genetic testing?
genetic testing that determines whether an individual has inherited a gene mutation that exhibits age-dependent penetrance.
What gene mutation is most likely to be associated with male breast cancer?
BRCA2
What are the BRCA genes involved with?
DNA repair
What is the major symptom of malignant hyperthermia
Crash during anesthesia involving certain trigger agents.
What is the treatment for familial hypercholesterolemia?
cholestyramine (clears cholesterol through feces) + statin (blocks HMG CoA Reductase, rate limiting step of cholesterol production).
What is the problem and how do you treat hereditary hemochromatosis?
iron overload - phlebotomy.
How do you treat homocystinuria?
(methionine metabolism disorder) 1st line - treat with B6 (pyridoxine), cofactor for apoenzyme.
What is a pseudogene?
nonfunctional vestigial genes (such as those in the global family) that are remnants of previously functional genes.
What is spinal muscular atrophy and what causes it?
problem of motor function, caused by survival motor neuron (SMN1) gene mutation - AR.
Define genetic heterogeneity
Different gene -> same phenotype
What is Bardet-Biedl?
condition including obesity, polydactyly. Caused by 18 different genes (genetic heterogeneity) that affect cilia.
What does ‘sensitivity’ measure?
proportion of those with disease who are detected (true positive / all positive)
What does ‘specificity’ measure?
Proportion of those who are disease free who test negative (true negative / all negative)
What is the treatment for medium chain acyl dehydrogenase deficiency?
avoid fasting
What is Duchenne Muscular Dystrophy, how is it inherited?
X-linked disorder associated with loss of dystrophin, important structural protein. Rock-hard calves.
What is difference between DMD and BMD?
Becker’s is less severe, some protein vs. DMD, no protein.
Give for example of tumor suppressor genes whose mutations lead to disease
1) BRCA1
2) BRCA2
3) Retinoblastoma
4) familial adenomatous polyposis (polyps in colon)
What causes familial hypercholesterolemia?
LDL receptor deficiency
What causes osteogenesis imperfecta?
mutation in a collagen gene.
What is the mechanism by which huntington’s disease acts?
triplet repeat produces a mutant gene product due to a polyglutamine repeat that acts to kill cells in which they are expressed. Gain of function mutation.
