The U.S. Food and Drug Administration approved on Wednesday a new treatment made by Ultragenyx Pharmaceutical Inc. for a rare genetic disorder that can dramatically reduce life expectancy.

The drug is designed to treat patients with mucopolysaccharidosis type VII, or MPS VII, a condition caused by an enzyme deficiency that affects tissue and organs, including the heart, and stunts growth.

The disorder affects fewer than 150 patients worldwide.

The drug, Mepsevii, was given to 23 patients who were treated for up to 164 weeks, the FDA said. After 24 weeks, patients taking the drug were able to walk on average 18 meters further within six minutes than those who did not receive the treatment.