PEDS Flashcards
2 mo old with constipation, lethargy, hypotonia, macroglossia, umbilical hernia, large anterior fontanelle
Congenital hypothyroidism
3do w/jaundice. Mom and patient Rh positive. Tbili 6, direct 0.5. AST, ALT normal. Most likely cause of jaundice?
UDP glucuronosyltransferase deficiency - Crigler-Najjar
Deficiency in what enzyme causes elevated arginine in plasma and CSF? What does the enzyme produce?
- Arginase deficiency (urea cycle enzyme)
- Urea and ornithine
sx - spastic diplegia, growth delay, abnl mvts
tx - arginine-free, low-protein diet
What is the major aa in the blood that transports excess ammonia from peripheral tissues to the kidney?
Glutamine
Deficiency in what causes hyperhomocysteinemia?
Vit B6, B12 and folate (B9) def
Citrullinemia and ornithine transcarbamylase deficiency causes excess of what? These are disorders of what cycle?
Orotic acid
Urea cycle - cause hyperammonemia
Hydroxylation and decarboxylation of what forms serotonin?
Tryptophan
DM, bronze-colored lesions that blister and scale, GI sx and anemia are signs of what?
Glucagonoma (from alpha-cells of pancreas)
dx - elevated serum glucagon
Abd pain, gallbladder stones, constipation, hyperglycemia, and steatorrhea are signs of what?
Somatostatinoma
inhibits insulin, glucagon, secretin, CCK secretion and GI motility
Intractable diarrhea, hypokalemia, dehydration, hypotension and achlorhydria are signs of what?
VIPoma
vasodilates
xeroderma pigmentosa has a defect in what process?
nucleotide excision repair - AR
endonuclease problem
kid with hx of recurrent lymphadenitis and skin infections. Dihydrorhodamine flow cytometry is not green, which is characteristic of normal neutrophils. Disease? How else do you diagnose it and what does it measure?
Chronic granulomatous disease - X-linked; unable to kill CATALASE producing organisms
Nitroblue tetrazolium test - dark blue. Assesses superoxide production (NADPH oxidase mutation)
Inc AFP in amniotic fluid indicates what?
NTD
Dec AFP in amniotic fluid indicates what?
Down syndrome
Inc acetylcholinesterase into amniotic fluid indicates what?
NTD
Only humoral immune def with no peripheral immature and mature B cells (no CD19+)
Bruton X-linked agammaglobulinemia
Mutation in BTK
Patients with Bruton agammaglobulinemia have inc susceptibility to what?
Encapsulated pyogenic bacteria (Strep pneumo, H influenza, Pseudomonas)
defect in tyrosine kinase –> no B cell maturation
Affects both B and T cell maturation. Prone to bacterial, viral, fungal and protozoan infections
SCID
- Adenosine deaminase def
Leukocyte adhesion def is due to deficiency in what?
CD18
lack common beta chain of integrin molecules.
Delayed umbilical cord separation
Hyper IgM syndrome is due to a deficiency in what?
CD40L
Def in TH cells deficient in expression of CD40L.
B cells present but no class switching. High IgM, low IgG, IgA, IgE.
Recurrent bacterial viral fungal and protozoal infx
What conditions can cause elevated urine orotic acid? How can you differentiate the two via sx?
- Hereditary orotic aciduria (defect in UMP synthase) - phys and mental retardation, megaloblastic anemia
- Ornithine transcarbamylase deficiency - failure to thrive, hyperammonemic encephalopathy (impaired urea synth)
PKU causes a deficiency of what and an excess of what? Why?
Tyrosine def, phenylalanine excess - phenylalanine hydroxylase converts phenylalanine to tyrosine
How does PKU cause fair complexion?
Excess phenylalanine inhibits tyrosinase, which is needed for production of melanin.
What vitamin can treat measles infection by reducing comorbidities (eg diarrhea, pneumonia), recovery time, and length of hosp stay?
Vit A
What vitamins in breast milk content is typically insufficient for nutritional needs of the newborn?
Vit D and K
Differential finger clubbing and cyanosis without blood pressure or pulse discrepancy are pathognomonic for what?
PDA complicated by Eisenmenger syndrome (reversal of shunt flow from L–>R to R–> L)
Hypoketotic hypoglycemia can occur after a period of fasting if a patient has a defect in fatty acid B-oxidation. What enzyme defect causes this defect?
acyl-CoA dehydrogenase (MCAD)
Def in this enzyme prevents formation of FADH2, NADH and ATP or ketone bodies
Carnitine def has similar features
What is needed to transport fatty acids into the mitochondria for b-oxidation?
Carnitine