Genetic Disorders II Flashcards
Tx for lysosomal storage
enzyme replacement
substrate reduction
molecular chaperones
tay sachs disease
Gm2 - gangliosidoses storage disease
common in jews of European descent
motor and mental problems - 6 months of age
blindness and death by age 2-3
progressive neuronal destruction
cherry red spot in macula
Gm2 gangliosidose
tay sachs
hexosaminidase alpha-subunit deficiency
tay sachs
sphingomyelinase deficiency
nieman pick A and B
accumulation in sphingomyelin
common in ashrkenazic jews
type B - organomegaly - no CNS involvement - survive until adulthood
type A niemann pick
more common
- manifest at birth
- death within 3 years
protuberant abdomen (hepatosplenomegaly), failure to thrive, vomiting, fever, lymphadenpaothy, psychomotor dysfunction
Dx of nieman pickmann type A
liver or bone marrow Bx
-look for sphingomyelinase activity
niemann pick type C
mutation in NPC1 or NPC2
-cholesterol transport
cholesterol and gangliosides Gm1 and Gm2 accumulation
hydrops fetalis, neonatal hepatitis
-progressive neuro degeneration beginning in childhood with ataxia, dystonia, psychomotor regression
NPC1
mutated in nieman pick C
gaucher disease
autosomal recessive
mutation in glucocerebrosidase
accumulation of glucocerebroside
type I more common - non-neuronopathic - some enzyme
type II - neuronopathic - NO enzyme - death at early age
type III - intermediated
glucocerebrosidase
mutated in gaucher disease
type I gaucher disease
in european jews
- non-neuronopathic
- splenomegaly and lymphadenopathy
mucopolysaccharidoses
deficient enzyme that degrade glycosaminoglycans
coarse facial features, hepatosplenomegaly, corneal clouding, valve thickening, joint stiffness, mental retardation
hurler syndrome
MPS 1-H
deficient alpha-1 iduronidase
onset 6-24 months
death age 6-10 (cardiovascular)
hunter syndrome
MPS II
lacking corneal clouding - less severe than hurler
von gierke disease
glycogen storage disease
deficient glucose 6 phosphatase
-hepatic enlargement and hypoglycemia
hepatic type - treatable - but with late complications
mcardle disease
glycogen storage disease
muscle cramps after exercise, low lactate after exercise
deficient muscle phosphorylase
pompe disease
glycogen storage disease
deficient acid maltase
-cardiac involvement prominent (cardiomegaly)
alkaptonuria
ochronosis - blue black pigment of ears, nose, cheeks
-autosomal recessive
deficient homogentistic oxidase
blocks phenylalanine metabolism
homogentistic acid accumulation
-black color in urine
clinically evident - age 30s
giemsa stain
G-banding
-to determine karyotype
G-band organization
arm (p,q)
region
band
sub-band
Xp21.2
chromosome X, p arm, region 2, band 1, sub band 2
aneuploidy
not an exact multiple of 3
caused by nondisjunction
and anaphase lag