lysinemia: an inborn error of metabolism in which the lack of certain enzymes leads to an inability to metabolize the amino acid lysine; characterized by muscular weakness and mental retardation
inborn error of metabolism: any of a number of diseases in which an inherited defect (usually a missing or inadequate enzyme) results in an abnormality of metabolism
housemaid's knee: swelling of the bursa in the knee (due to trauma or excessive kneeling)