Result: In particular, the most frequent substitutions, by genotyping analysis, are present at codon 36 [
M36I alone (7 cases) or associated with
L10V (2 cases)], at codon 63 [
L63P alone (5 cases) or associated with
V77I (2 cases)] and at codon 77 [
V77I (5 cases)], while
L10V was always found in association with
A71V or
M36I.