Analysis of the inter-alpha-trypsin inhibitor polymorphism in west Africa: description of a new allele, ITI*7.

Inter-alpha-trypsin inhibitor (ITI) phenotypes were classified in the West African population of Cabo Verde by polyacrylamide gel isoelectric focusing, followed by immunofixation and silver staining. Gene frequencies of the alleles ITI1, ITI2, ITI3, and ITI4 were calculated to be 0.532, 0.153, 0.307 and 0.002, respectively. A new rare allele, ITI7, was found, providing evidence for further genetic variability of the ITI protein. The ITI7 allele frequency has been determined to 0.006. The assumption that allele ITI*3 may be used to characterize populations of African origin is supported by our data.