RT Journal Article SR Electronic T1 A novel mutation in ornithine transcarbamylase gene causing mild intermittent hyperammonemia JF Saudi Medical Journal JO Saudi Med J FD Prince Sultan Military Medical City SP 1229 OP 1232 DO 10.15537/smj.2015.10.12127 VO 36 IS 10 A1 Sarar Mohamed A1 Muddathir H. Hamad A1 Altaf A. Kondkar A1 Khaled K. Abu-Amero YR 2015 UL http://smj.org.sa/content/36/10/1229.abstract AB We report a 3-year-old Saudi boy with recurrent episodes of vomiting, poor feeding, and altered mental status accompanied by an intermittent mild hyperammonemia, and a large elevation of urinary orotic acid. Sanger sequencing of the ornithine transcarbamylase (OTC) gene revealed a novel hemizygous deletion at the fourth nucleotide of intron 4 (c.386+4delT) in the proband and his asymptomatic mother. This novel mutation in the OTC gene is responsible for the late-onset phenotype of OTC deficiency.