CH 5: Genetics

Question 1

what are polymorphisms

Answer 1

genetic variations

Question 2

what is a mutation

Answer 2

permanent change in DNA

Question 3

what is an inherited (familial) disease

Answer 3

inherited chromosomal abnormality of one or more parents

Question 4

what is Marfan Syndrome

Answer 4

dominant, inherited defect in the FBN1 gene encoding the extracellular glycoprotein fibrillin-1
prevents TGF-b which causes bone overgrowth
causes skeletal abnormalities, ocular changes (lens dislocation), and cardiovascular lesions (mitral valve prolapse)

Question 5

what does fibrilin-1 do

Answer 5

glycoprotein that is a major component of microfibrils found in the extracellular matrix and forms elastic fibers

Question 6

what is Ehlers-Danlos Syndome

Answer 6

dominant disorder that causes mutations in genes that encode for collagen and its modifying enzymes
effects skin (hyperextensible), joints (hyperextensible), bowl (rupture), and large vessels

Question 7

what is familial hypercholesterolemia (FH)

Answer 7

dominant disorder that impairs hepatic clearance of LDL
leads to increased serum cholesterol levels which causes premature atherosclerosis
cholesterol deposits along tendon sheaths

Question 8

what is a xanthoma

Answer 8

papule or nodule typically in tendon sheaths due to lipid deposits
under the microscope, cells are light and have a foamy protoplasm (foam cells)

Question 9

which organelle is the key component of the intracellular digestive system

Answer 9

lysosome

Question 10

what is Tay-Sachs Disease

Answer 10

recessive disease where there is a mutation on chromosome 15 which causes severe deficiency of hexosaminidase A
GM2 gangliosides (lipids) cannot be catabolized so they build up in the nerve cells
prevalent in Ashkenazic Jews
presents with cherry red spots in retina, motor and mental deterioration, and dementia
leads to a complete vegetative state

Question 11

what is Sandhoff Disease

Answer 11

recessive deficiency of hexosaminidase B (HEXB) which results in neuronal injury and also affects the liver, pancreas, and kidney

Question 12

what is Neimann-Pick Disease (type A/B)

Answer 12

most common out of the three types
primary defect in nonenzymatic lipid transport (transport of free cholesterol from lysosomes to cytoplasm)
at birth: hydrops fetalis (severe swelling), hepatitis, and neurologic damage

Question 13

what is Neimann-Pick Disease (type C)

Answer 13

most common type of lysosomal storage disorder
recessive disease where there is a mutation in the glucocerebrosidase
this causes glucocerebrosides (lipids in nerve sheaths) to accumulate in macrophages leading to Guacher cells
type 1: affects spleen and bone marrow
type 2+3: affects CNS
high probability of causing Parkinson due to the disease leading to the accumulation of synucleins (brain proteins)

Question 14

what is Guacher Disease

Answer 14

most common type of lysosomal storage disorder
recessive disease where there is a mutation in the glucocerebrosidase
this causes glucocerebrosides (lipids in nerve sheaths) to accumulate in macrophages leading to Guacher cells
type 1: affects spleen and bone marrow
type 2+3: affects CNS
high probability of causing Parkinson due to the disease leading to the accumulation of synucleins (brain proteins)

Question 15

what are Guacher cells

Answer 15

enlarged macrophages due to the presence of distended lysosomes which are filled with glucocerbrosides
start to resemble wrinkled tissue paper

Question 16

what is Von Gierke Disease (type 1)

Question 17

what is mcardle disease (type 5)

Question 18

what is pompe disease (type 3)

Question 19

what is karyotping

Question 20

define euploid

Question 21

define aneuploidy

Question 22

decode 47,XY,+21

Question 23

define inversion in terms of a mutation