The mutations are sorted by region and their locations in the CFTR gene and then listed under the regions with the highest number of mutant chromosomes. Only mutations found 2 or more times and which exceeded 1% of the study population are listed. Detailed descriptions of the mutations may be obtained from the following references: E60X (G. Malone et al., pers. comm.); 1078delT (Claustres et al., 1992); 1161delC (M. Schwarz et al., pers. comm.); 296+12T->C (H. Cuppens et al., pers. comm., note: this mutation had not been confirmed by RNA analysis); G91R (Guillermit et al., 1993); S1235R (Cuppens et al., 1993); Q552X (Devoto et al., 1991); 2143delT (Dörk et al., 1992); 3272-26A->G (Fanen et al., 1992); 394delTT (Claustres et al., 1993); S1251N (Kälin et al., 1992; Mercier et al., 1993a); Y122X (Chevalier-Porst et al., 1992); 2184insA (A. Kälin et al., pers. comm.); 3821delT (White et al., 1991); R1283M (Cheadle et al., 1992); 457TAT->G (Ravnik-Glavac et al., 1993; C. Férec et al., pers. comm.); 1677delTA (Ivaschenko et al., 1991); R1070Q (Mercier et al., 1993b); 2183AA->G (Bozon et al., 1994); 711+5G->A (Bisceglia et al., 1994); T338I (Saba et al., 1993); R1066C (Fanen et al., 1992); 1811+1.2kbA->G (formerly 3601-111G->C; X. Estivill and M. Chillón, pers. comm.); 1949del84 (Granell et al., 1992); 1609delCA (Cuppens et al., 1992; Chillón et al., 1992); 3905insT (N. Malik et al., pers. comm.); M1101K (Zielenski et al., 1993); Y1092X (Bozon et al., 1994); I148T (Bozon et al., 1994); 3120+1G->A (M. Macek et al., pers. comm.); A559T (Cutting et al., 1990); S1255X (Cutting et al., 1990); Q359K/T360K (Shoshani et al., 1992); S549I (Kerem et al., 1990); R347H (Cremonesi et al., 1992); 1898+5G->T (J. Zielenski et al., pers. comm.).