Lysosomal Storage Diseases

Question 1

• 5 year old girl
• hepatosplenomegaly
• anemia
• thrombocytopenia
• bone pain
• nromal development and intelligence

A. Fabry disease
B. Gaucher disease type I
C. I-cell disease
D. Metachromatic leukodystrophy
E. Tay-Sach’s disease

Answer 1

B. Gaucher disease type I

hepatosplenomegaly is charcteristic of Gaucher
part of pioneering of ERT

Question 2

• 8 year old boy
• recurrent fever w/out infection
• excruciating pain all over body
• angiokeratoma found in buttock & scotum

A. Fabry disease
B. Gaucher disease type I
C. I-cell disease
D. Metachromatic leukodystrophy
E. Tay-Sach’s disease

Answer 2

A. Fabry disease

X-linked
females may show some symptoms
only CNS symtpom is increased risk of stroke
renal failure leading to death
ERT available
disorder of α-galactosidase which results in systemic accumulation of glycosphingolipids
with α-galactosyl terminal moieties, predominantly globotriasylceremides

Question 3

• college student in good health
• upper respiratory infection
• decreased patellar reflex
• mild ataxia
• sensation loss in feet
• sibling with similar symptoms in 20s and now in wheelchair and loss of bladder control

A. Fabry disease
B. Gaucher disease type I
C. I-cell disease
D. Metachromatic leukodystrophy
E. Tay-Sach’s disease

Answer 3

D. Metachromatic leukodystrophy

MLD is caused by deficiency of arylsulfatase A. Clinical manifestations include ataxia, gait disturbance, loss of speech and blindness. It is characterized by accumulation of galastosylsulfatide (and to a certain extent lactosylsulfatide, a globoside) in the white matter of the CNS and in peripheral nerves. There are late infantile and juvenile forms, and clinical manifestations include gait disturbance,
mental regression, urinary incontinence, blindness, loss of speech, quadriparesis, peripheral neuropathy, seizures,
behavioral disturbances and dementia.

Question 4

Gaucher disease enzyme:
A. Branched-chain ketoacids dehydrogenase deficiency
B. Glucocerebrosidase deficiency
C. Hexosoaminidase A deficiency
D. I-cell disease
E. Sphingomyelinase deficiency

Answer 4

B. Glucocerebrosidase deficiency

Question 5

Maple syrup urine disease enzyme
A. Branched-chain ketoacids dehydrogenase deficiency
B. Glucocerebrosidase deficiency
C. Hexosoaminidase A deficiency
D. I-cell disease
E. Sphingomyelinase deficiency

Answer 5

A. Branched-chain ketoacids dehydrogenase deficiency

Question 6

Tay-Sachs disease enzyme
A. Branched-chain ketoacids dehydrogenase deficiency
B. Glucocerebrosidase deficiency
C. Hexosoaminidase A deficiency
D. I-cell disease
E. Sphingomyelinase deficiency

Answer 6

C. Hexosoaminidase A deficiency

Question 7

Niemann-Pick disease type A
A. Branched-chain ketoacids dehydrogenase deficiency
B. Glucocerebrosidase deficiency
C. Hexosoaminidase A deficiency
D. I-cell disease
E. Sphingomyelinase deficiency

Answer 7

E. Sphingomyelinase deficiency

Question 8

ER chaperones calnexin and calreticulin are required so that N-linked proteins are not trapped in teh ER. Regarding the ER chaperones, which one of the following statements is incorrect?
A. ER chaperons are lectins that bind to carbohydrate ligands on N-linked glycoproteins
B. ER chaperones bind to oxo-reductases and recruit their action in the refolding process.
C. ER chaperones slow down the protein folding rate, so taht newly synthesized proteins fold properly and minimize mis-folding.
D. ER chaperones guide N-linked glycoproteins from one processing enzyme to another so taht the appropriate sugar tags are removed during the transport of a glycoprotein from the ER to the Golgi
E. ER chaperones do not remove the carbohydrate chain from the protein after it has refolded.

Answer 8

D. ER chaperones guide N-linked glycoproteins from one processing enzyme to another so taht the appropriate sugar tags are removed during the transport of a glycoprotein from the ER to the Golgi