Ultragenyx, a Novato-based biotech company that makes drugs for rare diseases, today reported that it plans to acquire Dimension Therapeutics in a cash transaction valued at about $151 million.

The merger agreement was finalized Monday and, if approved by shareholders, the deal could close by the end of the year. Ultragenyx will pay $6 a share for all outstanding shares of Dimension common stock. Ultragenyx has sufficient cash resources to make the deal, which has been approved by both company boards.

Cambridge-based Dimension had entered a merger agreement with Regenxbio, announced in August. That deal will be scuttled in favor of the Ultragenyx offer. Ultragenyx will pay Dimension’s $2.85 million termination fee to Regenxbio for canceling that deal.

Dimension has developed advanced gene therapies that will be useful for Ultragenyx, which makes drugs for rare genetic diseases such as X-linked hypophosphatemia (XLH), a bone disease characterized by phosphate-wasting due to excess fibroblast growth factor 23, a hormone that regulates phosphate excretion and vitamin D production by the kidney. The disease, affecting about one out of every 20,000 people, depletes minerals from bone, leading to weakness and pain as well as skeletal abnormalities.

XLH has been linked to some 260 different gene mutations in a section of the X chromosome. Patients with the disease have low phosphorus in the blood that affects bone health. People can get XLH with no genetic history, as a genetic fluke. Others inherit the disease from parents. The condition is linked to the X chromosome and is dominant. Men have one X chromosome; women have two. Daughters get their fathers’ X chromosome and one of their mother’s. Sons get their father’s Y chromosome and one of their mother’s. As a result, if a man has XLH, all his daughters will have the disease but none of his sons. Each child, son or daughter, of a mother with XLH will have a 50 percent chance of getting the disease.

The North Bay Business Journal covers Sonoma, Solano, Marin and Napa counties, with total population of about 1.3 million. Out of that population, an estimated 67 people have XLH.

Ultragenyx also makes UX007, a purified synthetic seven-carbon fatty-acid triglyceride used to treat long-chain fatty-acid oxidation disorders that render the body unable to convert such fatty acids into energy.

Ultragenyx, founded in 2010, has Emil Kakkis as its CEO and president. Kakkis retired from his position as chief medical officer at BioMarin, also based in Novato but with major operations in San Rafael. Ultragenyx had a net loss of $71.3 million in the fourth quarter of 2016, and a net loss of $246 million for all of 2016.

James Dunn covers technology, biotech, law, the food industry, and banking and finance. Reach him at: james.dunn@busjrnl.com or 707-521-4257.