A nonsynonymous G>A substitution was found at coding cDNA nucleotide 23 (c.23G>A) in exon 1 in the I/St strain. The amino-acid substitution was positioned in the cytoplasmic region of the leader sequence in the propeptide, changing amino-acid 8 from arginine to histidine (p.R8H or p.Arg8His). (J:114302)