Sequence analysis revealed that a CC pair in the open reading frame was changed to AAATA. This nucleotide substitution results in the proline codon 278 (CCT) to be replaced with tyrosine and lysine codons (AAATAT) (p.P234delinsKY) without affecting the rest of the open reading frame. This highly conserved proline residue is near the second catalytic domain. Expression of transcript from this allele does not appear to be affected by this mutation. It is predicted to be a gain-of-function mutation.