IEM Flashcards

1
Q

Zellweger spectrum disorder

hepatocerebrorenal syndrome
neonatal adrenoleukodystrophy

A

decreased peroxisomal function leading to limited oxidation of long chain FA

prominent forehead, wide open fontanel, epicanthal folds, hypertelorism, broad and flat nasal bridge, micrognathia

hypotonia, poor feeding, cataracts, chondrodysplasia punctate, renal cortical microcysts

Labs:
absent/decreased peroxisomes
increasee VLC FA (C22, C24, C26) NBS

supportive treatment geared towards symptoms

death usually by 1 year of age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Urea cycle

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

infants with galactosemia are at risk for infections with ___

A

E.Coli!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what to do if you have hyperammonemia

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

pathway for hypoglycemia workup

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Maple syrup urine disease
MSUD

AR

A

branched chain amino acids (leucine, isoleucine, valine) cannot be broken down beyond the alpha-ketoacids

normal at birth, symptoms within first few days to weeks
poor feeding, vomiting, lethargy tachypnea

by 4 days: alternating lethargy/irritability, hypotonia/hypertonia, dystonia, apnea, seizures, signs of cerebral edema

Labs:
- KETONURIA
- MAPLE SYRUP SMELL IN URINE = ketoacids
- METBOLIC ACIDOSIS
- hypoglycemia

Tests:
- urine dinitrophenylhydrazine test: + white precipitates

if breastfeeding, may delay symptoms until 4-10 days of age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Methylmalonic aciduria
MMA

A

deficiency of methylmalonyl-CoA isomerase
required cobalamin/Vit B12

increased risk of bacterial infections, FTT
dyspmorphic features (some): high forehead, broad nasal bridge, epicantahl folds, smooth philtrum, triangular mouth

vomiting, dehydration, lethargy, hepatomegaly

labs: metabolic acidosis (incr anion gap), ketonuria, hypocalcemia, increased lactate
NEUTROPENIA/THROMBOCYTOPENIA
normal to low glutamine
HYPERAMMONEMIA- can have resp alkalosis–> mistake for UCD

this has more severe neurologic outcomes
likely renal transplant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

PKU
Phenylketonuria

A

typical insidious onset in early infancy
MUSTY OR MOUSY URINE ODOR

diagnosis: urine detection of phenylpyruvic acid = +blue-green color

low phe diet
liver transplant leads to complete correction

outcome depenent on age of diagnosis/management
- BEST OUTOME if control by 2 weeks of age

classic: if initiate low phe diet within 1st 3 weeks, may have close to normal intelligence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

affects of maternal PKU on infant

A

IUGR
brain growth
myelination
neutrotransmitter synthesis
increased risk fo CHD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what direction of lens subluxation in homocystinuria

A

DOWNWARD

upward= Marfan’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what cofactor helps in pyruvate carboxylase deficiency

A

biotin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

glycogen storage disease presenting with lactic acidosis, hypoglycemia, hepatomegaly

A

von Gierke

GLUCOSE-6-PHOSPHATASE

possible bleeding diathesis secondary to liver failure
increased risk for infection

poor prognosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

mode of inheritance for OTC deficiency

A

x-linked recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Niemann-Pick disease type A

A

lysosomal storage disease

first month of life with HSM, nervous system deterioration

macular cherry red spot, clear cornea, foam cells on bone marrow biopsy

A+B due to sphingomyelinase defect

type B = no eye or CNS involvement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Gaucher disease type I/II

A

Ashkenazi Jewish descent

defects in enzyme glucocerebrosidase

HSM and neurologic manifestations
NO EYE INVOLVEMENT
bone marrow biopsy = Gaucher cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

pyruvate dehydrogenase deficiency

A

mitochondrial disorder

presents in childhood with developmental delays, poor muscle tone/weakness, seizures, ataxia or choreoathetosis, GLOBAL CEREBRAL ATROPHY

ABSENT CORPUS CALLOSUM

labs:
anion-gap metabolic acidosis
elevated lactate and pyruvate

assessing abnormal enzyme activity in white blood cells or skin fibroblasts

no treatment, uniformly fatal

17
Q

triad for urea cycle defect presentation

A

hyperammonemia
primary respiratory alkalosis
normal serum glucose

18
Q

non-ketotic hyperglycinemia

A

lethargy
hypo or hypertonia
seizures
obtundation
respiratory failure
HICCUPS

absent corpus callosum
EEG with burst suppression –> hypsarrhythmia

elevated urin, blood, CSF glycine

no reliably effective treatment, poor prognosis

19
Q

ketotic hyperglycinemia
aka propionic aciduria

A

AR
deficiency of propionyl-CoA carboxylase deficiency

similar presentation to non-ketotic hyperglycinemia but NO ketones in urine/blood

20
Q

homocystinuria

AR

A

DOWNWARD dislocated lens
risk for osteoporosis, seizures, thrombosis

elevated methionine and homocystinuria

deficiency in either vitamin 12 dependent factors or cystathionine synthetase

treat by supplementing with pyridoxine, cysteine, folate
limiting dietary methionine

21
Q

Boy with golden-brown granular pigementations on his cornea, difficulty speaking, abnormal jerky movements of his extremities. Also has liver disease

A

Dx: Wilson’s disease- inability to transport copper to the liver = copper deposition in liver, cornea, basal ganglia, renal tubules

Tx: D-penicillamine- chelates copper to reduce serum levels

22
Q

brittle, kinky, steely hair

A

Menke’s disease

defect in the membrane copper transport channel leading to poor absorption and cellular distribution of copper

Tx: copper injections

23
Q

Defect in Gaucher I/II

A

Glucocerebrosidase

24
Q

Defect in Niemann Pick A/B

A

sphingomyelinase

25
Q

Defect in Tay Sachs

A

Hexosaminidase-A

26
Q

Defect in Fabry disease

A

alpha- galactosidase

27
Q

Defect in Krabbe disease

A

Beta-galactosidase

28
Q

exclusively breastfed baby just introduced to formula now with new onset seizure, vomiting, poor PO

had been normal prior

labs: hypoglycemia, elevated LFTs, +urine reducing substances

A

fructosemia!

deficiency in fructose-1-phosphate aldolas = cant breakdown fructose

BM= lactose = galactose + glucose
Cow’s milkd formula= sucrose = fructose +glucose

galactosemia- presents after ANY feeding introduced

29
Q

where does the metabolic acidosis come from in galactosemia?

A

results from renal tubular dysfunction NOT from excessive lactate concentrations

30
Q

infant with poor feeding, vomiting in first 2-3 days, lethargy, jaundice, hepatomegaly, liver failure, renal tubular dysfunction

A

galactosemia

absence of galactose-1-phosphate-uridyltransferase
cant break down galactose into glucose

NON-GLUCOSE reducing substances in urine

occurs in both formula and BM fed babies

cataracts occur after 2 weeks of age due to excess galactilol but regress with good dietary control of lactose

increased risk of E.coli sepsis

liver issues can progress to cause coagulopathy and hypoalbuminemia

31
Q

infant with symmetric muscle weakness, cardiomegaly, congestive heart failure (big heart on CXR). Poor prognosis with death typically at < 1 year

A

Pompe’s Disease
glycogen storage disease due to deficiency of lysosomal alpha-glucosidase

32
Q

infant with glycogen storage disease. Affects liver, kidney, GI track

spares muscle and brain

A

von Gierke disease

deficiency in glucose-6-phosphatase