Maciamo, thank you for the information,
All of my family on 23andMe are like this, for *0401: - HLA-DRB*0401 : rs6910071 (A/A), rs3817964 (T/T) , and rs660895 (A/A), except for my dad and myself who are instead: rs6910071 (A/G), rs3817964 (T/T), and rs660895 (A/A).
Given the one G allele...