Lysosomal Storage Disorders

Question 1

What is and are the clinical features of Hurler Syndrome (MPS Type I)?

Answer 1

Mucopolyssaccharidoses

Clinical features-
Coarse facies 
Corneal clouding
Hirsutisms
Hepatosplenomegaly
Thick Skulls
Severe Intellectual Disability

*Reduced alpha-L-iduronidase activity in WBCs

Question 2

What is and are the clinical features of Hunter Syndrome (MPS Type II)?

Answer 2

Mucopolyssaccharidoses, X-linked recessive

Clinical features-
Coarse facies
Organomegaly
Joint Contractures (short, skeletal abnorm)
Skin that is “pebbly”, esp over upper back
Progressive Deafness

Question 3

What causes and are the clinical features of Gaucher Disease?

Answer 3

Sphingolipidoses

Causes-
Infantile: decreased beta glucosidase activity. Presents in 1st-2nd year of life, CNS deterioration with heptomegaly

Chronic Juvenile: not as severe, no CNS involvement, splenomegaly, thrombocytopenia, pancytopenia

Clinical Features-
Hepatosplenomegaly
Bone pain
Easy bruisability
Short stature
Thrombocytopenia
Osteosclerosis
Lytic lesions

Question 4

What causes and are the clinical features of Tay Sachs Disease

Answer 4

Autosomal Recessive

Cause-
Hexosaminidase A enzyme deficiency

Clinical features-
Normal development for first 9 months
Lethargy
Hypotonia
Exaggerated startle reflex
Cherry red spot on the retina
Macrocephaly
Blindness and seizures
Death by 5 yo

• Ashkenazi Jews, French Canadians
• No hepatosplenomegaly like Niemann-Pick

Question 5

What causes and are the clinical features of Niemann-Pick Disease?

Answer 5

Clinical features-
CNS deteriation
Hepatosplenomegaly
Cherry red spot on the retina

Question 6

How do mitochondrial disorders present?

Answer 6

Defects in oxidative phosphorylation, defect in aerobic measures. Heart, muscles, and nerves suffer

Clinical features-
Myopathy
Short stature
Sensorineural deafness
Seizures
Dementia
Ophthalmoplegia
Developemental delays
Stroke