Arginine 109 to glutamine mutation in a girl with ornithine carbamoyl transferase deficiency.

We studied DNA from 29 families with at least one member with ornithine carbamoyl transferase (OCT) deficiency and have found a mutation in the TaqI site within exon 5 of the OCT gene in a female presenting at the age of 21 months. Hybridisation with site specific oligonucleotides shows that the mutation is a C to T substitution resulting in a glutamine for arginine substitution at amino acid 109.