Genetics

Question 1

What IL is absent in X-SCID?
What is the most important reason for death?
Males or females affected?
Two predisposed breeds?
What two types of Ig levels are decreased?

Answer 1

IL-2 receptor mutation = deficiency in humoral and cell mediated reactions
(IL-2 and IL-2R are responsible for T helper activation, growth of T, B, NK cells)
Mortality associated with recurrent infections
Males only affected
Basset Hounds & Corgis
IgG and IgA levels are low (IgM is normal)

Question 2

What defect does grey collie neutropenia have?

Answer 2

Cyclic neutropenia: cyclic defect in all hematopoietic lines and myeloperoxidase deficiency

Defect in G-CSF signaling
(Also cyclic deficiency in EPO, thrombopoeitin, IL-1, IL-6)
cyclic neurtopenia
If live long enough, hepatic/renal amyloidosis are seen

Question 3

What mutation in CLAD seen?
What kind of CS?
High predisposed breed?
What CBC abnormality seen?

Answer 3

CD18 mutation
Neutrophil adhesion/LPS recognition abnormality
Recessive disease in Irish setters
High neutrophil counts due to unable to extravasate

Question 4

Chediak-Higashi

Answer 4

Smoke blue Persian cats with partial occulocutaneous albanism, thrombopathia, susceptibility to infection
Leukocytes contain eosinophilic granules
Hair has melanin clumps
Tx: G-CSF, IL-2

Question 5

Glanzmann’s thrombothenia

Answer 5

Otterhounds, Pyrenees
GPIIb/IIIa (fibrinogen receptor) deficiency
Decreased fibrinogen in alpha-granules

Question 6

Primary ciliary dyskinesia (PCD) is inherited in an autosomal recessive mode. What breed is high predisposed to this condition?

Answer 6

Old English Sheepdog

Question 7

Pelger huet anomaly

What is the characteristics seen on blood smear?

Answer 7

Hyposegmentation of granulocytes and monocytes in the presence of a full mature, coarsely clumped chromatin pattern
Can be confused with a degenerative left shift, but this is benign
Autosomal dominant
Australian sheepdog, cockers, heelers