Arginosuccinic Aciduria in a 4-Year-Old Girl: Neurological Symptoms and Hair Abnormalities

A 4-year-old girl with arginosuccinic-aciduria showed symptoms including mental retardation, seizures, ataxia, and abnormal hair, with normal ammonia and blood urea nitrogen levels despite an enzymic block in the urea cycle. Hair strength was significantly reduced, and although trichorrexis nodosa was not diagnosed, the hair's cystine content was notably low. The neurological symptoms' cause in this amino acid disorder remained speculative.