Metabolic disorders Flashcards
Case
CC: Poor weight Gain
K.A. 3mo/F , sees you for the first time with the chief complaint of
poor weight gain.
Pertinent in the birth history is history of
(+) feeding difficulties with frequent vomiting episodes
(+) prolonged jaundice
(+) poor weight gain
(+) history of seizures
Newborn screening: (+)
Nutritional History: Exclusively breastfed
PE:
Weight for age below -3 , Length for age below -3
lethargic , generalized hypotonia, (+) jaundice
(+) bilateral cataracts
(+) hepatomegaly
(+) splenomegaly
Laboratory:
CBC: WBC 9.0 Hgb 145 Hct .45 plt
Blood CS: NG5D
RBS: low
ABG: metabolic acidosis
Babygram: Normal chest, hepatomegaly, paucity of bowel pattern
What is the primary impression?
Galactosemia
What are the basis for the primary impression?
Basis:
Typical signs and Symptoms at Birth/ Hx
o feeding difficulties with frequent vomiting episodes
o prolonged jaundice
o poor weight gain
o history of seizures
o Newborn screening: (+)
Physical findings
o Poor growth within the first few weeks of life
o Jaundice
o Bleeding from coagulopathy
o Liver dysfunction and/or hepatomegaly
o Cataracts (sometimes as early as the first few days of
life)
o Lethargy
o Hypotonia
o Sepsis (E coli)
Lab Results:
o NBS (+) Galactosemia
o RBS: low
o ABG: metabolic acidosis
What are the differentials?
- Sepsis/ TORCH
Rule in:
Vomiting, poor feeding
Poor weight gain
seizures
Cataracts, Hepatosplenomegaly -
TORCH
Galactosemia patients are at
increased risk for E. coli sepsis
Rule out:
(+) NBS: Galactosemia
jaundice WBC normal, Blood CS: NG
- IEM
Rule in:
Vomiting, poor feeding
jaundice
Poor weight gain
seizures
ABG: metabolic acidosis
RBS: low
Rule out:
(+) NBS: Galactosemia
- GERD
Rule in: Vomiting, poor feeding (+)
Poor weight gain
Severely wasted, severe
stunted
Rule out:
NBS: Galactosemia
Jaundice, seizure
Cataracts, hepatosplenomegaly
4.GI malformations: (Atresia, pyloric stenosis)
Rule in:
Vomiting, poor feeding
Poor weight gain
Severely wasted, severe
stunted
Rule out:
(+) NBS: Galactosemia
Jaundice, seizure
Cataracts, hepatosplenomegaly
Babygram: Paucity of gas bowel
patterns
- RTA
Rule in:
Vomiting, poor feeding
Poor weight gain
Severely wasted, severe
stunted
ABG: metabolic acidosis
Rule out:
(+) NBS: Galactosemia
Jaundice, seizure
Cataracts, hepatosplenomegaly
work-up
o A positive (ie, abnormal) indication on the newborn
screen must be followed by a Direct enzyme assay
using erythrocytes which shows Deficient activity of
galactose-1-phosphate uridyl transferase
demonstrable in hemolysates of erythrocytes, which
also exhibit increased concentrations of galactose-1-
phosphate
Additional in work up for cases of FTT:
o Basic work-up may include CBC (for anemia), Blood
gas (RTA, metabolic disease), TFTs, UA
o (renal and metabolic disease), ESR/CRP (sign of
inflammation/infection), stool for fat, pH, reducing
o substances, occult blood, ova and parasites, sweat
chloride, lead, TB and HIV.
Treatment
Treatment:
o Early diagnosis and treatment have improved the
prognosis of galactosemia
o Elimination of galactose from the diet reverses growth
failure and renal and hepatic dysfunction.
o Various milk substitutes are available (casein
hydrolysates, soybean-based formula).
Prognosis
Prognosis:
o Most patients with severe galactosemia who do not
receive treatment often do not survive the newborn
period. Even with appropriate dietary therapy, most
patients have at least 1-2 long-term complications
(ovarian failure with primary or secondary
amenorrhea, decreased bone mineral density,
developmental delay, and learning disabilities that
increase in severity with age
Acidic urine odor
Methylmalonic acidemia (methylmalonic acid)
Cabbage urine odor
hepatorenal tyrosinemia, methionine malabsorption
Cat urine
3-methylcrotonyl CoA dehydrogenase deficiency, multiple carboxylase deficiency
Maple syrup/burnt syrup
MSUD
mouse/musty
PKU (phenylacetate)
rancid butter
hepatorenal tyrosenemia
Sweaty feet
isovaleric acidemia, glutaric aciduria, Type II (Isovaleric acid)
Clinical approach to a newborn infant with a suspected metabolic disorder
p. 178
- Clues in Hx:
- Marriage is consanguineous, hx of recurrent abortion,
hx of unexplained neonatal death in siblings especially
assoc with acidosis, coma and convulsions, sibling
diagnosed suffering an IEM - Clues in PE
- Tachypnea, apnea, lethargy
- Hyper/hypotonicity
- Hepatosplenomegaly, ambiguous genitalia, jaundice
- Dysmorphic or coarse facial fx
- Rashes/patchy hypopigmentation
- Ocular (cataracts, lens dislocation, pigmentary
retinopathy
- Intracranial hemorrhage
- Unusual odors - Laboratory
a. ABG – metabolic acidosis with inc anion
gap, primary respiratory alkalosis
b. Plasma ammonia elev
c. Hgt – hypoglycemia
d. Serum and urine ketones – ketosis and
ketonuria
e. TB, DB, IB, elev LFTs – hyperbilirubinemia
f. Lactic acidosis
g. High lactate/pyruvate ratio
h. Non-glucose reducing substances in urine
i. CBC – neutropenia, thrombocytopenia
