Genetic disorders II

Question 1

what enzyme is defective in Tay Sachs disease?

Answer 1

hexosaminidase A

Question 2

what product is built up in Tay Sachs disease?

Answer 2

gangliosides

Question 3

what tissue is affected in Tay Sachs disease? what is the histologic appearance?

Answer 3

1. CNS neurons 2. balooned out

Question 4

what enzyme is defective in gaucher disease?

Answer 4

glucocerebrosidase

Question 5

what product is built up in gaucher disease?

Answer 5

glucocerebrosides (glucose + ceramide)

Question 6

what tissue is affected in gaucher disease? what is the histologic appearance?

Answer 6

1. RES (spleen, liver, bone marrow) 2. crinkled tissue paper (granular, fibrillary)

Question 7

what enzyme is defective in niemann pick disease?

Answer 7

sphingomyelinase

Question 8

what product is built up in niemann pick disease?

Answer 8

sphingomyelin cholesterol

Question 9

what enzyme is defective in Hurler’s or Hunter’s disease?

Answer 9

a-L-iduronidase or L-iduronidate sulfatase

Question 10

what product is built up in hurler’s or hunter’s disease?

Answer 10

mucopolysaccharides

Question 11

what tissue is affected in hurler’s or hunter’s disease? what is the histologic appearance?

Answer 11

1. CNS, eye, RES, BV, heart 2. foam cells

Question 12

what enzyme is defective in pompe disease?

Answer 12

a-1,4-glucosidase (acid maltase)

Question 13

what product is built up in pompe disease?

Answer 13

glycogen

Question 14

what tissue is affected in pompe disease? what is the histologic appearance?

Answer 14

1. heart, SM 2. clear

Question 15

what enzyme is defective in von gierke disease?

Answer 15

glucose-6-phosphatase

Question 16

what tissues are affected in von gierke disease? what is the histologic appearance?

Answer 16

1. liver, kidney, skin 2. foamy, vacuolated

Question 17

what tissue is affected in niemann pick disease? what is the histologic appearance?

Answer 17

1. CNS, RES 2. foamy, vacuolated (zebra bodies)

Question 18

what are the features of autosomal recessive inheritance?

Answer 18

1. uniform expression 2. complete penetrance 3. early onset 4. loss of function (protein) 5. both sexes involved 6. skips generations

Question 19

what enzyme is defective in alkaptonuria?

Answer 19

homogentisic acid oxidase

Question 20

what product accumulates in alkaptonuria? what is the effect?

Answer 20

1. homogentisic acid 2. binds to collagen in CT, tendons, cartilage to form blue-black pigmentation

Question 21

degenerative arthropathy is a complication of what disease?

Answer 21

alkaptonuria

Question 22

the lysosomal storage diseases display what type of inheritance?

Answer 22

autosomal recessive

Question 23

what is the mutation involved in Tay Sachs disease? what chromosome is it on?

Answer 23

1. frameshift mutation in HexA gene 2. chromosome 15

Question 24

what are the clinical signs of tay sachs disease?

Answer 24

mental retardation, large head, blindness, cherry red macula

Question 25

what are the clinical signs of gaucher disease?

Answer 25

massive liver, spleen, lymph nodes, skeletal problems,

Question 26

imiglucerase is a drug therapy for what disease?

Answer 26

gaucher disease

Question 27

what type of mutation is associated with niemann pick disease?

Answer 27

missense

Question 28

what are zebra bodies?

Answer 28

niemann pick disease - engorged lysosomes on EM view with concentric lamellated myelin figures

Question 29

niemann pick type C is characterized by a deficiency in what process?

Answer 29

cholesterol transport

Question 30

what are the clinical signs of niemann pick type A disease?

Answer 30

hepatosplenomegaly, enlarged lymph nodes, retinal cherry red spot, shrunken brain gyri, widened sulci

Question 31

what are the clinical signs of niemann pick type C disease?

Answer 31

neonatal hepatitis, progressive neurological damage

Question 32

the mucopolysaccharidoses are characterized by inability to degrade what substance?

Answer 32

glycosaminoglycans

Question 33

what is the primary complication of the mucopolysaccharidoses?

Answer 33

subendothelial arterial deposits in coronary arteries

Question 34

Hurler syndrome shows what type of inheritance? Hunter's?

Answer 34

1. autosomal recessive 2. XLR

Question 35

what are the morphologic changes of von gierke disease? untreated clinical features?

Answer 35

1. hepatomegaly, renomegaly, intracytoplasmic accumulations 2. failure to thrive, stunted growth, hypoglycemia, hyperlipidemia, xanthomas, bleeding tendency

Question 36

what are the morphologic changes of mcardle disease? untreated clinical features?

Answer 36

1. skeletal muscle only - glycogen accumulation in sarcolemma 2. painful cramps associated with strenuous exercise

Question 37

what are the morphologic changes of pompe disease? untreated clinical features?

Answer 37

1. mild hepatomegaly, ballooning lysosomes, cardiomyopathy 2. massive cardiomegaly, muscle hypotonia, cardiorespiratory failure within 2 years

Question 38

the mutated gene for pompe disease is located on what chromosome?

Answer 38

17