A SPECIFIC CYSTIC-FIBROSIS MUTATION (T3381) ASSOCIATED WITH THE PHENOTYPE OF ISOLATED HYPOTONIC DEHYDRATION

We carried out molecular screening for mutations in the cystic fibrosi s transmembrane regulator (CFTR) gene in eight children of Sardinian d escent seen because of hypotonic dehydration associated with hyponatre mia, hypochloremia, hypokalemia, and metabolic alkalosis; none had pul monary or pancreatic involvement, All the patients had the T3381 mutat ion either in homozygosity or compound heterozygosity with another CF mutation, The T3381 mutation was not detected in patients with CF who had classic symptoms or in healthy persons of the same descent, These data suggest that the T3381 mutation is associated with a specific mil d CF phenotype.