The
carbohydrate moiety of the
orosomucoid (ORM) molecule shows microheterogeneity [1] and the
pteridine-containing variant seems to be
tumor-specific [2-4]. However, there also exists a genetic (
protein-related) polymorphism coded by the ORM1 and ORM2 loci on chromosome 9 [5, 6]. To investigate the relationship between ORM1 gene products and the development of
carcinoma, we analyzed the ORM1 phenotypes of desialated sera from 125 patients with
carcinoma. The allele frequencies were estimated for ORM1*F1 0.556, ORM1*F2 0.012 and ORM1*S 0.432. In comparison to healthy individuals from the same geographical area [6] the ORM1 S phenotypes are significantly more frequent in
carcinoma patients. The patients' sera frequently showed additional ORM-positive
proteins which focused slightly cathodically to the ORM 2 A band. These
proteins may represent posttranslational modifications of the ORM1*S allele product. Whether these modifications are
tumor-specific and related to the
carbohydrate moiety of the molecule must be confirmed in further studies.