Intracellular calcium in cystic fibrosis heterozygotes.

Increased intracellular calcium (Ca) has been reported in several cell types in cystic fibrosis (CF). Because CF is an autosomal recessive trait examination of asymptomatic obligate carriers (HZ) of the gene is a powerful way to determine the relevance of this observation to the abnormal gene product. We report here that Ca as determined by atomic absorption spectrophotometry in cultured skin fibroblasts and circulating lymphocytes is greater in HZ than in control cells. Since an intracellular Ca increase is expressed in HZ the Ca differences in CF likely reflect action of the gene product responsible for CF and not some secondary or tertiary effect of the disease.