The mutation is an A-to-G transition at coding nucleotide 1088, in the third of 5 exons, that replaces histidine with arginine at amino acid position 363 (p.H363R) of the protein. This highly conserved histidine is one of three copper-binding histidines in the second copper-binding domain (CuB) of the protein and is essential for its enzymatic activity. (J:133116)