Explore rare diseases in clinical trials
Check which rare diseases are currently being frequently studied.
See also our popular diseases glossary and drug database.
Starting by letter
To open the rare diseases glossary, select a letter from the list below.
Rare diseases starting with “t”
- 1
Testicular leiomyosarcoma
Testicular leiomyosarcoma is an extremely rare cancer that develops from smooth muscle cells in or around the testicle, affecting primarily middle-aged and older men, though cases in younger individuals have been documented without any known risk factors.
- 3
Thrombotic thrombocytopenic purpura
Thrombotic thrombocytopenic purpura is a rare blood disorder that causes dangerous blood clots to form throughout the body, blocking blood flow to vital organs like the brain, kidneys, and heart. Without urgent treatment, this condition can be life-threatening, but with proper care, most people can recover and manage their health.
- 1
Toxic epidermal necrolysis
Toxic epidermal necrolysis is a rare but extremely serious skin condition that causes large areas of skin to blister and peel away, leaving raw, painful wounds that resemble severe burns. This life-threatening reaction is usually triggered by certain medications and affects at least 30% of the body’s surface, including sensitive areas like the mouth, eyes, and genitals.
- 7
Tuberous sclerosis complex
Tuberous sclerosis complex is a rare genetic disease that causes non-cancerous tumors to develop in multiple organs throughout the body, particularly in the brain, kidneys, heart, skin, and lungs. While some people live with few symptoms, others may experience seizures, developmental delays, and serious organ complications that require lifelong monitoring and care.
- 5
Turner’s syndrome
Turner’s syndrome is a genetic condition that affects only females, occurring when one of the X chromosomes is partially or completely missing. While there is no cure, early diagnosis and treatment can help girls and women with this condition lead healthy, productive lives.


