A. Is there a family history of neonatal losses? Such a history is highly suspicious for metabolic disease caused by enzyme deficiencies. These diseases typically are transmitted in an autoso-mal-recessive or occasionally X-linked fashion, making the recurrence risk for these families significant.
B. Is there associated vomiting? Can be nonspecific, or excessive with hyperammonemia.
C. Does patient have an unusual odor? Organic acids are volatile and thus can be associated with an unusual odor of sweat, urine, or earwax. Maple syrup urine disease (MSUD) is often suspected from sweet-smelling earwax. A foul "sweaty feet" or "cat urine" odor can occur in several of the organic acidemias.
D. If available, what were the newborn screening results? Newborn screening studies in many states include many of the organic acidemias, fatty acid oxidation defects, and urea cycle defects. Check screening results of child or other family member, if available. Because of limitations of screening tests, a negative study cannot be relied on to rule out disease (specifically, several urea cycle defects and energy production defects). Due to residual enzyme function, a sample obtained before the onset of symptoms may be normal, even in an affected patient. Abnormal results must be verified with acute samples (see later discussion under V, Plan).
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