Metabolic Disease

Question 1

Amino Acid Disorders

Answer 1

• 6 AA disorders picked up on PA NBS
• Feeding difficulties
• Failure to Thrive
• Abnormal odors (PKU - mousy, musty odor) (Trimethylaminuria-fishy odor)
• Treatment:
• Dietary restriction offending amino acid
• Supplement Cofactors

Question 2

Organic Acidemias

Answer 2

• 9 OA picked up on PA NBS
• Catastrophic neonatal presentation (metabolic acidosis, ketonuria, encephalopathy, coma)
• Abnormal odors (Glutaric acidemia - sweaty socks; MSUD - sweet/maple syrup)
• Treatment: restrict offending amino acid(s), cofactor supplements, carnitine supplements)

Question 3

Fatty Acid Oxidation Disorders

Answer 3

• Cause of 5-6% of SIDS cases
• Symptoms may be most apparent or severe during times of prolonged fasting or febrile illness
• Hypoketotic hypoglycemia, hyperammonemia
• Fasting intolerance, recurrent vomiting, lethargy, “Reye-like” liver failure, cardiomyopathy (long-chain defects, CPT), Adult onset muscle weakness, cramping
• Treatment: Avoid prolonged fasting
• Carnitine for certain disorders

Question 4

Urea Cycle Disorders

Answer 4

• Catastrophic neonatal presentation
• Elevated ammonia levels, liver disease
• Older children present with behavioral or gait disturbances during acute illnesses
• OTC - X-linked; all others autosomal recessive
• Treatment: low protein diet, ammonia scavengers (plus B vitamins), Branch chain amino acid supplements, arginine or citrilline supplements, liver transplant

Question 5

Disorders of Carbohydrate Metabolism

Answer 5

• Catastrophic neonatal presentation or food intolerances associated with vomiting, FTT, lactic acidosis (symptoms depend on specific disorder)
• Galactosemia picked up on NBS
• Treatment (restrict offending carbohydrate(s), provide cornstarch for some disorders)

Question 6

Metabolism

Answer 6

All the chemical reactions that occur within the cells of the body

Question 7

Inborn Errors of Metabolism (IEM) are a group of disorders caused by geme mutations that

Answer 7

• Reduce/eliminate enzyme activity OR
• Inhibit proper utilization of enzyme cofactors OR
• Inhibit the synthesis or breakdown of intracellular chemicals