Addressing Rare Diseases—Gene Therapy and Beyond

Almost 30 million people in the United States—about 1 in 10 of the country’s population—live with a rare disease. The rarity of these conditions can make them difficult to diagnose and study. Effective treatments are available for only a few hundred of the roughly 7,000 rare diseases that have been identified.

Each February, NIH observes Rare Disease Day to raise awareness about rare diseases, the people they affect, and scientific research. Every day of the year, researchers at NIAID and NIAID-funded institutions collaborate with patients and their families to better understand, diagnose, and treat a spectrum of rare conditions—from immune deficiencies to infectious diseases.

NIAID physician-scientists have a strong track record of successfully treating primary immune deficiency diseases (PIDDs)—genetic diseases of the immune system. Last month, an international team including NIAID researchers reported progress in developing gene therapy to treat X-linked chronic granulomatous disease, a PIDD characterized by frequent and sometimes life-threatening bacterial and fungal infections. Most volunteers who received the experimental gene therapy remained infection-free even after stopping prophylactic antibiotics to prevent severe infections.

Scientists also are evaluating gene therapy for treatment of X-linked severe combined immunodeficiency (X-SCID), a PIDD in which the development and function of white blood cells is impaired. A gene therapy approach co-developed by NIAID scientists successfully re-built the immune systems of eight infants born with this fatal disease, researchers reported in spring 2019. This therapy also has improved the health and quality of life of older children and young adults with X-SCID who experienced complex medical problems after receiving live-saving bone marrow transplants to treat the condition. The new Blood and Immune Deficiency-Cellular Therapy Program at the NIH Clinical Center promises to foster further advances in gene therapy and other treatments for people with PIDDs and other rare blood and immune system diseases.

The past year also marked progress in understanding and addressing rare infectious diseases. Among other advances, NIAID-supported scientists developed an experimental model to study prion diseases and uncovered additional evidence for an association between acute flaccid myelitis and infection with non-polio enteroviruses.

Learn more about NIAID's rare disease research by exploring the following resources:

• NIAID offers detailed information about more than two dozen PIDDs. Read about Types of Primary Immune Deficiency Diseases.
• Learn more about Prion Diseases, a related group of rare, fatal brain diseases that affect animals and humans.
• Read about NIAID research to tackle Eastern Equine Encephalitis Virus, a mosquito-borne virus that can cause life-threatening brain inflammation.
• Neglected Tropical Diseases are prevalent in the developing world but rare in the United States. Read NIAID’s recent blog post Marking the First World Neglected Tropical Diseases Day.