Question Explanations

Question 1

I-Cell Disease

Answer 1

• Autosomal recessive
• lysosomal storage disease caused by deficient enzyme (uridine diphospho-N-acetylglucosamine:N-acetylglucoseaminyk-1-phosphotransferase in the Golgi complex that tags lysosomal enzymes with mannose-6-phosphate
• lysosomal enzymes are secreted by the cell
• inclusion bodies prominent on electron microscopy

Question 2

Glycogen degradation disorders

Answer 2

McArdle’s disease, Pompe’s diseases, Cori disease, Von Gierke’s disease

Question 3

Refsum Disease

Answer 3

disorder in myelin formation due to a disorder in fatty acid oxidation or syntheses. Peroxisomes are involved in long-chain fatty acid metabolism so there is a disorder in peroxisomes in this disease.
- Presents with progressive neurologic damage at a young age

Question 4

DiGeorge Syndrome

Answer 4

• Developmental failure of 3rd and 4th pharyngeal pouches
• 22q11 microdeletion
• Presentation: T-cell deficiency, lack of thymus, hypocalcemia, lack of parathyroid and abnormalities of heart, great vessels and face

Question 5

SCID - Severe Combined Immunodeficiency

Answer 5

defective cell-mediated and humoral immunity 
Etiologies: cytokine recepto defects, adenosine deaminase deficiency, MHC class II deficiency

Question 6

X-Linked Agammaglobulinemia

Answer 6

-complete lack of immunoglobulim due to disordered B-cell maturation
-due to mutated BTK - Bruton tyrosine kinase; X-linked
Presents with recurrent bacterial, enterovirus and giardia lamblia infections
- presents 6 months after birth, live vaccines (polio) must be avoided

Question 7

CVID - Common variable immunodeficieny

Answer 7

• LOW immunoglobulin due to B-cell or helper T-cell Defects

- increased rish for bacterial, enterovirus and giardia lamblia infections

Question 8

IgA Deficiency

Answer 8

• low serum and mucosal IgA - most common immunoglobulin deficiency
• increased risk for mucosal infection, especially viral
• present in celiac disease

Question 9

Hyper-IgM Syndrome

Answer 9

• elevated IgM
• due to mutated CD40L or CD40
• class switching inhibited - Low IgA, IgG and IgE –> recurrent pyogenic infections especially at mucosal sites

Question 10

Wiskot-Aldrich Syndrome

Answer 10

• Presents with Thrombocytopenia (increased bleeding), eczema and recurrent infections
• due to mutation in WASP gene; X-linked

Question 11

C5-C9 complement deficiency

Answer 11

increased risk for Neisseria infection

Question 12

C1 inhibitor deficiency

Answer 12

results in heriditary angioedeme - edema of skin and mucosal surfaces

Question 13

Karyolysis

Answer 13

basophilia of chromatin fades

Question 14

karyorrhexis

Answer 14

pyknotic nucleus undergoes fragmentation

Question 15

pyknosis

Answer 15

nuclear shrinkage and increased basophilia