Use of organic acids to provide insight into functional metabolic imbalances has evolved from historic diagnostic testing to investigate inborn errors of metabolism (IEM).

While the OAT is not designed specifically to diagnose classically defined IEMs, persistent marked elevations in OAs noted on the profile may indicate an undiagnosed underlying metabolic pathway defect. As such, further clinical investigation via an individual patient’s clinical presentation and the results of complementary laboratory tests may be warranted to guide more specific testing.

IEM are a class of inborn errors of metabolic pathways that are marked by accumulation (and usually toxic) organic acid metabolites in blood (i.e., organic acidemias) and increased excretion of organic acids in urine (i.e., organic acidurias). While individual IEMs are rare that typically become apparent clinically during the newborn period or early infancy, though milder – and even asymptomatic – forms may emerge in adolescence and adulthood.

Because of the life-threatening metabolic disturbances (acidosis and ketosis) that are associated with IEMs, an entire field of preconception and postnatal screening has arisen. Current newborn screening includes assessment of 34 core conditions which allows for early treatment intervention should a positive finding result.