Inborn Errors

Question 0

Infant with hypotonia, exaggerated startle, cherry red spot and normal abd exam.
Dx and how is it diagnosed?

What other three disorders have cherry red macula?

Answer 0

Tay Sachs, dx with hexosaminidase A assay

Gaucher and Niemann Pick also have cherry red macula but have HSM, Farbers has cherry red spots, joint probs and skin nodules

Question 1

How is galactosemia diagnosed?

What would be seen in the urine?

Answer 1

Galactose-1-p activity in RBCs, and reducing substances would be seen in the urine

Question 2

Two diseases with cherry red spots and HSM?

How to differentiate them?

Answer 2

Gaucher’s has easy bruising 2/2 thrombocytopenia, bone lytic lesions

Question 3

Cleft palate, FTT, congenital heart disease, flat nasal bridge with arched eyebrow like a Greek helmet

Dx and what type of mutation?

Answer 3

Wolf hirschhorn; deletion (4p-)

Question 4

What is a child with hemihypertrophy at risk of developing, and how should they be screened?

Answer 4

Tumors: Wilms, adrenal carcinoma, hepatoblastoma

Should have q3m renal ultrasounds and AFP

Question 5

Dx and likely finding in a 6 yr old with worsening school performance, hearing deficit and leukodystrophy on MRI?

Answer 5

X-linked adrenoleukodystrophy

Plasma very long chain fatty acids are elevated

Question 6

Test for amino acid disorders vs. organic acidemias

Answer 6

Amino acidopathies: serum amino acids

Organic acidemias: urine organic acids

Question 7

Ptosis, ophthalmoplegia, chewing/swallowing issues, absence of pectoralis

Answer 7

Moebius

Question 8

Infantile spasms, agenesis of corpus callosum, retinal lacunae

Answer 8

Aicardi Syndrome