Abstract More than 900 mutations and more than 200 dif- ferent polymorphisms have now been reported in the cys- tic fibrosis transmembrane conductance regulator (CFTR) gene. Ten years after the cloning of the CFTR gene, the complete scanning of the 27 exons to identify known and novel mutations remains challenging. Rapid accurate identification of mutated alleles is important for prenatal diagnosis, for cascade screening in families at risk of cys- tic fibrosis (CF) and for understanding the correlation be- tween genotype and phenotype. In this study, we report the successful use of denaturing ion-pair reverse-phase high performance liquid chromatography (D-HPLC) to analyse rapidly the complete coding sequence of the CFTR gene. With 27 pairs of polymerase chain reaction primers, we optimised the temperature conditions re- quired for the analysis of each amplicon and validated thetest conditions on samples from a panel of 1552 CF pa- tients who came from France and other European coun- tries and who had mutations and polymorphisms located in the various melting domains of the gene. D-HPLC identified 415 mutated alleles previously characterised by denaturing gradient gel electrophoresis and DNA se- quencing, plus 74 novel mutations reported here.This new technique for screening DNA for sequence variation was extremely accurate (it identified 100% of the CFTR alle- les tested so far) and rapid (the complete CFTR gene could be analysed in less than a week). Our approach should reduce the number of untyped CF alleles in popu- lations and thus decrease the residual risk in couples at risk of CF. This technique may be important not only for CF,but also for many other genes with a high frequency of point mutations at a variety of sites. Introduction With an incidence of about 1 in 3000 live births in Cau- casians of European extraction (Welsh et al. 1995), cystic fibrosis (CF) is one of the most common lethal diseases in childhood. CF can result from many different mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (ABCC7, MIM 602421). In addition to the ∆F508 deletion, which accounts for about 66% of all CF alleles world-wide, more than 900 different mutations have been reported throughout the 27 exons of the CFTR gene by the Cystic Fibrosis Genetic Analysis Consortium (http://www.genet.sickkids.on.ca). CF mutations have also been found in other clinical diseases such as congenital bilateral absence of the vas deferens (CBAVD; Chillon et al. 1995; de Braekeleer and Ferec 1996; Dumur et al. 1990; Mercier et al. 1995), dis- seminated bronchiectasis (Girodon et al. 1997; Pignatti et al. 1995) and chronic pancreatitis (Cohn et al. 1998; Sharer et al. 1998). The particularly large number of dif- ferent alleles, combined with marked variation in their distribution and frequency according to geographic and ethnic origin (Estivill et al. 1997; Tsui 1992) makes clini- cal testing for mutated alleles particularly difficult. It is only in a few populations, such as those in Brittany (France) and in Quebec (Saguenay Lac St Jean) that 98%–100% of the mutated alleles have been identified so far (de Braeke- leer et al. 1998; Férec et al. 1992). During the last ten years, the development of technol- ogy for mutation screening has been extremely productive with the appearance of powerful techniques such as poly- merase chain reaction (PCR), single strand conforma- tional polymorphism (SSCP) (Orita et al. 1989), chemical and enzymatic cleavages (Cotton et al. 1988; Babon et al. 1999), denaturing gradient gel electrophoresis (DGGE) (Lerman and Silverstein 1987) and, more recently, dena- turing ion-pair reverse-phase high-performance liquid chromatography (D-HPLC) (Oefner and Underhill 1998). D-HPLC is an automated technology for mutation screen- ing based on the separation of heteroduplexes from ho- C. Le Maréchal · M. P. Audrézet · I. Quéré · O. Raguénès · S. Langonné · C. Férec Complete and rapid scanning of the cystic fibrosis transmembrane conductance regulator (CFTR) gene by denaturing high-performance liquid chromatography (D-HPLC): major implications for genetic counselling Hum Genet (2001) 108 : 290–298 DOI 10.1007/s004390100490 Received: 8 January 2001 / Accepted: 12 February 2001 / Published online: 4 April 2001 ORIGINAL INVESTIGATION C. Le Maréchal · C. Férec (✉) EFS-Bretagne, EPI 01-15, Site de Brest, CHU, Brest; France e-mail: claude.ferec@univ-brest.fr, Tel.: +33-2-98445064, Fax: +33-2-98430555 M. P. Audrézet · I. Quéré · O. Raguénès · S. Langonné · C. Férec Laboratoire de Génétique Moléculaire, EPI 01-15, CHU, 29200 Brest, France © Springer-Verlag 2001