ABGC Boards: Metabolics (Well-enlightened)

What causes inborn errors of metabolism? correct answers Enzyme deficiencies What causes the symptoms of IEMs? correct answers 1. Accumulation of substrate, or 2. Deficiency of product T/F: Individuals with IEMs usually have dysmorphic features correct answers F What is the usual inheritance pattern of IEMs? correct answers Recessive T/F: IEMs usually have effective treatment options correct answers T Why are IEMs common targets of NBS? correct answers Effective, preventive treatments available What is the defect in PKU? correct answers Defect in phenylalanine hydroxylase, which converts phenylalanine to tyrosine What does high phenylalanine cause? correct answers Accumulation of phenylketones What is the most common defect in CAH? correct answers Defect in 21-hydroxylase, which converts 17-hydroxyprogesterone into 11-deoxycortisol What does high 17-hydroxyprogesterone cause? correct answers Virilization in utero What is treatment for IEMs based on? correct answers Correcting metabolic imbalances With IEMs, how much enzyme activity is usually needed to avoid symptoms? correct answers ~10% of normal activity Which test is better for quantitative analysis of amino acids - plasma or urine? correct answers Plasma What circumstances are best for amino acid analysis? correct answers Fasting specimen What specimen is usually used for organic acid analysis? correct answers Urine Is organic acid analysis qualitative or quantitative? correct answers Can be either! What are examples of clinical scenarios in which amino acids and/or organic acids may be ordered? correct answers FTT, unexplained acute illness, DD, monitoring of therapies for known IEMs What specimen is usually used for acylcarnitine profile? correct answers Plasma