Metabolic

Question 1

most common metabolic condition

Answer 1

mitochondrial disease (1/5000 births)

Question 2

metabolic finding in early hyperammonemia

Answer 2

respiratory alkalosis (eventually leading to respiratory acidosis as they become more lethargic)

Question 3

metabolic conditions causing liver failure in the newborn

Answer 3

• tyrosenemia type 1
• galactosemia
• neiman-pick type C

Question 4

RED FLAGS for inborn errors mimicking CP

Answer 4

• normal MRI, abnormalities isolated to globus pallidus
• absence of hx of perinatal injury, regression
• consanguinity, fam hx
• isolated muscle hypotonia, rigidity (vs. spasticity)

Question 5

what should you RULE OUT in a mom with HELLP?

Answer 5

fatty acid oxidation disorder in baby

Question 6

what metabolic conditions present with a funny odor?

Answer 6

organic acidopathies

Question 7

mitochondrial disease - inheritance

Answer 7

most common type of inheritance = autosomal recessive.

Can also have maternal inheritance of mitochondrial disease, passed from mom to all children
- different levels of heteroplasmy affect the phenotype (not all clinically affected)

Question 8

elevated ketones in unwell newborn

Answer 8

think of type 1 diabetes or inborn error of metabolism

Question 9

urine tests for suspected metabolic condition

Answer 9

organic acids, amino acids, urinanalysis

Question 10

blood tests for suspected metabolic condition

Answer 10

glucose, lytes, ammonia, lactate, urate, amino acids, acylcarnitine profile, homocysteine, carnitine (total/free), copper/ceruloplasmin

Question 11

what three metabolites can you detect on an MRI/MRS?

Answer 11

creatine, lactate, NAA

Question 12

initial management of metabolic crisis - how do you decrease toxic substances/metabolites

Answer 12

• decrease catabolism (provide glucose)
• eliminate exogenous substrate (NPO, no protein)
• reduce endogenous substrate (scavenger medications, dialysis)

Question 13

PKU

Answer 13

phenylalanine hydroxylase deficiency (elevated Phe and low/normal tyrosine)
- do NOT get sick acutely, results in chronic dev delay

Question 14

MCAD

Answer 14

most common beta-oxidation defect, can’t produce ketones (hypoketotic hypoglycemia)

Question 15

features of mucopolysaccharidoses (MPS)

Answer 15

• developmental regression, coarse facies, many are treatable

Question 16

features of Gaucher disease

Answer 16

splenomegaly, bone disease

treatable - enzyme replacement

Question 17

name the condition:
presents with encephalopathy AND
anion gap acidosis, hyperammonemia, hypoglycemia

Answer 17

think of organic acidemias!

Question 18

name the condition:
presents with encephalopathy
AND
hyperammonemia
(normal glucose, no metabolic acidosis)

Answer 18

urea cycle disorder

Question 19

what are MCAD, VLCAD?

Answer 19

beta-oxidation defects, present with non-ketotic hypoglycemia

Question 20

what is a complication in a patient with a known beta-oxidation defect?

Answer 20

rhabdomyolysis!

Question 21

what top three tests would you send in a patient with developmental delay

Answer 21

1. microarray
2. fragile x
3. if female - test for retts

Question 22

how do you test for a mucopolysaccharidosis?

Answer 22

urine mucopolysaccharide screen

Question 23

how do you treat mucopolysaccharidosis?

Answer 23

enzyme replacement therapy, bone marrow transplant

Question 24

How is newborn screening done?

Answer 24

Tandem Mass Spectrometry (TMS)

Question 25

two most common metabolic conditions screened for on NBS?

Answer 25

PKU

MCAD

Question 26

what should you think of if you see a respiratory alkalosis?

Answer 26

hyperammonemia

Question 27

what should you think of if you see a child with a stroke, which doesn’t fit with the usual expected vascular distribution?

Answer 27

mitochondrial oxidative phosphorylation disorders

Question 28

What labs would you send to work up developmental delay?

Answer 28

1. microarray
2. fragile x
3. if female, MECP2 (Retts)
4. Metabolic studies

Question 29

how do you test for galactossemia?

Answer 29

urine reducing substances

GALT red blood cell screening test

Question 30

what do you give in pyridoxine dependant seizures?

Answer 30

Vitamin B6

Question 31

what do you give in methylmalonic aciduria?

Answer 31

Vitamin B 12

Question 32

what can cause an abnormal elevation of ammonia?

Answer 32

hemolysis of RBCs!

Question 33

what test should you do with OTC deficiency?

Answer 33

urine and plasma amino acids

Question 34

complication of fatty acid oxidation defect?

Answer 34

rhabdomyolysis, should check CPK!