Nature 344, 665 - 667 (12 April 1990); doi:10.1038/344665a0

A frame-shift mutation in the cystic fibrosis gene

Marga B. White^*, Jean Amos^†, Julie M. C. Hsu^‡, Bernard Gerrard^*, Paula Finn^† & Michael Dean^*

^* Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick, Maryland 21701, USA
^† Boston University Medical Center, Boston, Massachusetts 21128, USA
^‡ Wayne State University School of Medicine, Detroit, Minnesota 48201, USA.

CYSTICfibrosis (CF) is a common recessive lethal genetic disorder, affecting 1 in 1,600 Caucasians¹. The disease causes defective regulation of chloride-ion transport in exocrine cells^2–5. Although in all CF families the disease is linked to a locus on chromosome 7q31 (refs 6-11), there is clinical heterogeneity in the severity of the disease and the age at which it is diagnosed. CF is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene^12–13. A three-nucleotide deletion (F508) causing the loss of a phenylalanine residue in the tenth exon of the CFTR gene has been found on 70% of CF chromosomes^12–14 We have now characterized a CF family in which neither parent of the affected individual carries the common mutation, and identified a two-nucleotide insertion in the CF allele of the mother. The mutation introduces a termination codon in exon 13 of the CFTR gene at residue 821, and is predicted to result in the production of a severely truncated nonfunctional protein.