MINOR NEUROLOGICAL FINDINGS AS PRIMARY SY MPTOMS IN A CASE OF ORNITHINE TRANSCARBAMYLASE (OTC) DEFICIENCY

X-linked inherited OTC-deficiency is the most frequent inborn error of urea synthesis. Molecular heterogeneity is shown by more than 50 muta tions at the OTC-gene locus reflecting a broad clinical spectrum. We r eport on a normally developed 16 months old girl who never had coma or lethargy but presented with neurological symptoms such as minor ataxi a and increased muscular tonus and discrete athetoidal movements of th e upper extremities. EEG showed only minor abnormalities, in the MRI o f the brain enhanced, frontal and occipital periventricular signal int ensities were detectable. Biochemical findings were typical for OTC-de ficiency with a moderate hyperammonemia (up 332 mu mol/l), normal basi c acids in plasma and a high excretion of erotic acid and uracil in ur ine (735 and 370 mmol/mol creatinine resp.). DNA analysis showed a nov el G > T mutation at the intron1/exon1 boundary, which apparently led to an abnormal splicing of the DNA. After introducing a dietary and me dical treatment, neurological symptoms disappeared, blood ammonia norm al, MRI changes almost completely disappeared 3 months after therapy w as started. Discussion: This case illustrates that a selective screeni ng for inborn errors of metabolism should also be performed in patient s with minor neurological symptoms.