Metabolic Disorder Flashcards
Newborn with a high ammonia level, normal anion gap, and respiratory alkalosis. What metabolic disorder category is this likely to be?
Urea cycle defect (UCD)
Newborn with poor feeding, vomiting, elevated ammonia levels, and respiratory alkalosis and elevated citrulline levels
Citrullinemia-UCD
Child presents with ammonia level 2000μmol/L, low BUN, with respiratory alkalosis without ketoacidosis and high levels of orotic acid
Ornithine transcarbamylase deficiency (OTC)-UCD
What are the initial steps of urea cycle defect (UCD) management?
Reduce protein intake, correct respiratory alkalosis
Normal to high ammonia level with a high-anion gap acidosis. What metabolic category is this likely to be?
Organic acidemia
A neonate with severe ketoacidemia with or without elevated ammonia level, and long-term complication is associated with cardiomyopathy
Propionic acidemia
Which metabolic disease can cause encephalopathy and is associated with an odor of sweaty feet?
Isovaleric acidemia
Which metabolic disease presents with retinal hemorrhage and intracranial bleeding and can be mistaken for child abuse?
Glutaric aciduria type I
A 1-week-old presents with severe metabolic acidosis, poor feeding, opisthotonos, absent Moro reflex, seizures, and urine with a “caramel-like odor”
Maple urine syrup disease Treatment: restrict leucine intake
What is the category of these amino acids: valine, leucine, and isoleucine?
Three branched-chain amino acids
A 6-month-old has alopecia, encephalopathy; skin rash looks like acrodermatitis enteropathica
Biotinidase deficiency or holocarboxylase synthetase deficiency
A 2-year-old girl presents with seizures, tachypnea, and drowsiness; she has been having diarrhea, vomiting, and loss of appetite for the last few days. Her labs showed hypoglycemia, low ketones, and hyperammonemia
Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency (due to fatty acid oxidation defect, she is unable to increase ketone body production after glucose consumption during fasting or metabolic stress due to illness)
Child presents with a musty odor, eczema, fair skin and hair, and intellectual disability
Phenylketonuria (PKU)
Newborn with positive PKU on newborn screening. What is the next best step?
Start low-protein diet and a phenylalanine-free medical formula as soon as possible. Then confirm with genetic testing
What is the major consequence of delaying dietary restriction in children with PKU?
Irreversible intellectual disability in most children
Black pigments in the diapers, unusually dark urine few days after birth; when older, develops blue discolorations in the ear cartilage and palpable calcifications in the discolored areas, arthritic symptoms in the spine, hip and knee
Alkaptonuria
Child with an intellectual disability, normal aorta, pectus excavatum, increased risk of clotting, along with downward dislocation of the lens (ectopia lentis)
Homocystinuria (in Marfan syndrome the lens is dislocated upward and no intellectual disability)
Infant with failure to thrive, hepatomegaly; renal tubular acidosis may be associated with hepatoblastoma
Tyrosinemia type I (hepatorenal)
Type of tyrosinemia associated with intellectual disability, corneal ulcers, and painful skin lesions on the palms and soles
Tyrosinemia type II (oculocutaneous tyrosinemia)
A 4-week-old infant presents with vomiting, seizure, jaundice, poor weight gain, hepatosplenomegaly, cataracts, and reduced substance in the urine
Galactosemia (galactose 1-phosphate uridyltransferase deficiency)
Infant had sepsis before the diagnosis of galactosemia. What was the most likely cause?
Escherichia coli (E. coli)
Healthy infant presents with cataracts only. What is the most likely cause?
Galactokinase deficiency
A 4-month-old, doll-like face with prominent cheeks, short stature, thin extremities, protuberant abdomen, hepatomegaly, hypoglycemia, seizures, lactic acidosis, hyperuricemia, and hyperlipidemia
Type I glycogen storage disease (von Gierke disease)
What is the best management of infants with von Gierke disease?
Continuous feeding at night with nasogastric tube
Cramps with exercise, burgundy-colored urine after exercise, elevated creatine phosphokinase (CPK), and ammonia levels after exercise
McArdle disease (type V glycogen storage disease)
A 6-week-old infant previously normal presents with muscle weakness, hypotonia, large tongue, hepatomegaly, hypertrophic cardiomyopathy, congestive heart failure, elevated CPK, transaminases, and LDH; muscle biopsy shows vacuoles full of glycogen
Pompe disease (type II glycogen storage disease)
A previously healthy 7-month- old infant with new-onset seizures, vomiting, and lethargy that started after fruit juice was introduced
Fructokinase 1,6, diphosphatase deficiency
An 18-month-old with inguinal and umbilical hernias, now presents with progressive developmental delay, coarse facial features, macroglossia, macrocephaly >95%, hepatosplenomegaly, corneal clouding, retinal disease, and deafness
Hurler syndrome Mucopolysaccharide (MPS) type I
An 18-month-old boy, previously healthy, presents with progressive developmental delay, coarse facial features, macroglossia, macrocephaly >95%, hepatosplenomegaly, no corneal clouding
Hunter syndrome MPS type II (X-linked recessive)
Child previously normal presents with a progressive intellectual decline, temper tantrums, hyperactivity, destructive and aggressive behavior, pica and sleep disturbances, now becomes immobile and unresponsive
Sanfilippo syndrome MPS type III
Acroparesthesia or episodes of extremities with burning pain, anhidrosis, fever, proteinuria, hypertension, angiokeratomas (painless papules on the skin), and clouding of the cornea
Fabry disease (X-linked recessive)
A 3-year-old of Ashkenazi Jewish presents with severe splenomegaly, lytic bone lesions, and decreased glucocerebrosidase levels
Gaucher disease type I
A 2-month-old infant startles easily to any noise, does not diminish with repeated stimuli, hypotonia, progressive muscle weakness, extremity hypertonia, large head, noises trigger seizures, macular cherry-red spot, and no organomegaly
Tay–Sachs disease
A 4-year-old child, dysphagia, abnormal eye movement, ataxia, hepatosplenomegaly, cataplexy when scared, and narcolepsy
Niemann–Pick disease
Infant with a history of developmental delay, Myopathy, Encephalopathy, Lactic Acidosis, and Stroke
(MELAS) syndrome
Ptosis, ophthalmoplegia, ragged-red fiber myopathy
Mitochondrial DNA (mtDNA) mutation
An 18-year-old develops ophthalmoplegia, night blindness, ataxia, heart block, muscle weakness, proximal myopathy, short stature, and hypogonadism
Kearns–Sayre syndrome
A 12-year-old, ataxia, hypoactive or absent deep tendon reflexes, impaired vibratory and proprioceptive functions, hypertrophic cardiomyopathy, and diabetes mellitus
Friedreich ataxia
Boy, biting his lips, and fingers; normal at birth, had difficulty gaining weight in the 1st year of life, uric acid level is elevated
Lesch–Nyhan disease
What is the enzyme deficiency in patients with Lesch–Nyhan disease?
Hypoxanthine-guanine phosphoribosyltransferase (HGPRT)
How is Lesch–Nyhan disease transmitted?
X-linked recessive
Loss of developmental milestones; failure to thrive; truncal hypotonia; abnormal kinky hair, eyebrows, and eyelashes
Menkes disease or kinky hair disease
How is Menkes disease transmitted?
X-linked; causes an impaired copper intake
Child with cholesterol 650mg/dL, tendon xanthoma, father died at age 23 with a heart attack
Familial hypercholesterolemia
