By Julie Steenhuysen

(Reuters) - A company formed by genome pioneer Craig Venter will offer clients of a South Africa-based insurance company whole exome sequencing - sequencing all protein-making genes in the human genome - at a price that marks yet another dramatic decline in the cost of gene sequencing, the two companies said on Tuesday.

Venter's company, Human Longevity Inc, will provide the tests at a cost of $250 each through a special incentive program offered by Discovery Ltd, an insurer with clients in South Africa and the United Kingdom.

Venter, the U.S. scientist who raced the U.S. government to map the human genome 15 years ago for a cost of $100,000, said the $250 price point per whole exome marks a new low in the price of gene sequencing.

"It's our goal to really make this (sequencing) available to broad populations," he said in a telephone interview.

The multiyear deal gives Discovery's clients access to low-cost whole exome sequencing, tests that look only at the protein-making segments of DNA known as exons, which represent 2% of the genome but account for 85% of disease-causing mutations.

The deal also covers testing for whole genome and cancer genome sequencing services. Financial terms were not disclosed.

Until recently, whole genome sequencing - which maps all of an individual's 20,500 genes - was prohibitively expensive, costing about $20,000 just five years ago. As of last year, the average cost of whole genome sequencing fell to $1,500.

Whole exome sequencing costs range from $400 to $1,500, plus extra charges for analyzing the results.

For insurance company Discovery, exome sequencing will be offered through a behavioral wellness program that provides clients with tools and incentives to make lifestyle changes to help them stay healthy.

Discovery clients who choose exome screening will receive a comprehensive report detailing their risks for specific diseases and potential strategies to modify those risks. Discovery will provide the reports to clients through a network of physicians and genetic counselors.

Venter's company, which is based in San Diego, will receive de-identified data from participating Discovery clients, which it will use to build its library of genetic and health information. Such data is becoming highly prized by pharmaceutical companies as a faster means of drug research.

Last January, Human Longevity signed a multiyear deal to sequence and analyze tens of thousands of genomes for Roche Holding's Genentech unit in an effort aimed at identifying new drug targets and biomarkers.