Identification of common cystic fibrosis mutations in African-Americans with cystic fibrosis increases the detection rate to 75%

Am J Hum Genet. 1997 May;60(5):1122-7.


Cystic fibrosis (CF)--an autosomal recessive disorder caused by mutations in CF transmembrane conductance regulator (CFTR) and characterized by abnormal chloride conduction across epithelial membranes, leading to chronic lung and exocrine pancreatic disease--is less common in African-Americans than in Caucasians. No large-scale studies of mutation identification and screening in African-American CF patients have been reported, to date. In this study, the entire coding and flanking intronic sequence of the CFTR gene was analyzed by denaturing gradient-gel electrophoresis and sequencing in an index group of 82 African-American CF chromosomes to identify mutations. One novel mutation, 3120+1G-->A, occurred with a frequency of 12.3% and was also detected in a native African patient. To establish frequencies, an additional group of 66 African-American CF chromosomes were screened for mutations identified in two or more African-American patients. Screening for 16 "common Caucasian" mutations identified 52% of CF alleles in African-Americans, while screening for 8 "common African" mutations accounted for an additional 23%. The combined detection rate of 75% was comparable to the sensitivity of mutation analysis in Caucasian CF patients. These results indicate that African-Americans have their own set of "common" CF mutations that originate from the native African population. Inclusion of these "common" mutations substantially improves CF mutation detection rates in African-Americans.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Africa
  • Blacks / genetics*
  • Codon, Terminator
  • Cystic Fibrosis / diagnosis*
  • Cystic Fibrosis / genetics*
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics*
  • Frameshift Mutation
  • Genetic Testing
  • Humans
  • Male
  • Mutation*
  • Point Mutation
  • United States


  • CFTR protein, human
  • Codon, Terminator
  • Cystic Fibrosis Transmembrane Conductance Regulator