Sequana Therapeutics Inc. said it is closing in on twogenes that may be linked to asthma based on its DNAanalysis of blood samples from more than 1,000 diseasesufferers in three nations, including a remote island in theSouth Atlantic Ocean.
The La Jolla, Calif.-based company's scientists said thesearch for the genes has been narrowed to two smallregions on two chromosomes. The regions, they added,represent .1 percent of the human genome's 3 billion basepairs contained in 46 chromosomes.
Sequana is conducting its hunt for asthma genes in apotential $70.5 million collaboration with Germany-based Boehringer Ingelheim.
Mapping the probable locations of the two genestriggered two milestone payments to Sequana fromBoehringer Ingelheim for a combined $2 million. Sinceforming the alliance in June 1995, Sequana has received$13 million from the pharmaceutical company, whichbought rights to drugs based on the genes. Sequanaretained rights to develop diagnostic products.
In conducting its linkage analyses to create the physicalmap of where the genes may be found, Sequana first usedDNA samples from 300 closely related residents ofTristan da Cunha who were afflicted with asthma. Theisland is midway between Brazil and South Africa in theAtlantic Ocean and 30 percent of the residents areafflicted with the disease.
Once the likely regions were identified on thechromosomes of the Tristan da Cunha family members,Sequana validated the sites by analyzing DNA from about900 other asthma sufferers divided between two familygroups in Canada and China.
Kevin Kinsella, Sequana's president and CEO, said, "Weare delighted by the speed with which we've been able tofind linkage and narrow the interval in which the genesare located." He declined to speculate on when Sequanamight identify the genes.
In the U.S., about 5 percent of the population, or 13million people, are affected by asthma. Because it isconsidered a polygenic disease, researchers hope to find amajor gene that accounts for more than 10 percent ofasthma cases.
Sequana's stock (NASDAQ:SQNA) closed Wednesday at$11, down 12 cents. n
-- Charles Craig
(c) 1997 American Health Consultants. All rights reserved.