Ms. Phyllis Morel reported the first example of anti-Ok(a) in a Japanese woman. Blood Group System - Ok

Abbreviation - OK

ISBT Number - 024

The first example of anti-Oka was found in a Japanese woman and was identified by Morel and Hamilton. Since she had never been pregnant, the antibody most likely was the result of a prior blood transfusion. Two of her three siblings were also found to be Ok(a-). The Ok(a-) phenotype appears to be limited to the Japanese as the only other (two) donors who were Ok(a-) were also Japanese.

A monoclonal anti-Oka was produced following immunization with cells from a teratocarcinoma. This was used to study the biochemical properties of the Oka antigen. The antigen is expressed on a glycoprotein having molecular weights ranging from 35,000-68,000. The gene for Oka is located on chromosome 19p13.2, however, its function is unknown.