ABSTRACT
Argininosuccinic aciduria was first recognized in patients with chronic more indolent disease where the major manifestations were nonspecific, sometimes mild or moderate mental retardation [1-4]. This may reflect the unique features of the hair in this disorder, which brought many of the early patients to attention with apparent alopecia. The disorder presents also, and probably more frequently, in the classic neonatal hyperammonemic pattern of a typical urea cycle disease [5-10]. Sometimes these infants may be suspected clinically to be different from those with other urea cycle disorders because of the magnitude of the hepatomegaly.
