DETERMINATION OF CYSTIC-FIBROSIS CARRIER FREQUENCY FOR ZUNI NATIVE-AMERICANS OF NEW-MEXICO

The Zuni native Americans of the Southwest have an incidence of cystic fibrosis of approximately one in 333 or seven and one-half times that found for Caucasians. Earlier studies indicated that dF508 was not am ong the cystic fibrosis mutations causing this disease. Through a coll aborative study the R1162X mutation was found on 12 out of 12 cystic f ibrosis chromosomes from six Zuni patients. Because of the relative hi gh incidence of cystic fibrosis, we undertook a study to determine the carrier frequency of the R1162X mutation among randomly sampled indiv iduals. We found the carrier frequency in the general population for t he R1162X to be 6.7%, a very significant number when compared with the carrier frequency for all cystic fibrosis mutations in the Caucasian population of approximately 4%.