The disease was first described in 1970 by Hirata and colleagues in Japan.13 The syndrome has about 10 times the incidence in East Asia, particularly among Japanese, than in persons in Western Europe based on case reporting.13,16–22 The cases in East Asia (principally Japanese, with some Chinese and Korean subjects) are nearly all the result of polyclonal anti-insulin antibodies, but occasional cases, especially among persons of European descent, have had monoclonal anti-insulin antibodies mediating the syndrome without other evidence of a monoclonal gammopathy.14,15,20,23–25. This evidence concerns the gene INS and monoclonal gammopathy.