[Genetic study of a family of subjects with ankylosing spondylitis]

In a family of four patients with ankylosing spondylarthritis, the study of HLA typing has permitted to establish the dissociated transmission of the B27 antigen and the spondylarthritis: as a matter of fact, if the father and his two sons have the disease, and carry the B27, one of the daughters is also definitely affected with spondylarthritis according to New York criteria, and does not carry the B27. This young woman, also, does not present in her haplotype the genes of susceptibility to psoriasis, B13, B17, CW6, DR7, nor the antigens giving cross reactions with B27, type CREG, B7, B22, B40. So, this young woman seems to have inherited from her father a genetic predisposition toward the disease without transmission of antigen B27 and it is supposed that if this gene is linked to the HLA system by an unbalanced binding, it was transmitted after recombination in her father.