Tenosynovitis is the inflammation of the fluid-filled sheath (called the synovium) that surrounds a tendon, typically leading to joint pain, swelling, and stiffness. Tenosynovitis can be either infectious or noninfectious. Common clinical manifestations of noninfectious tenosynovitis include de Quervain tendinopathy and stenosing tenosynovitis (more commonly known as trigger finger)

Signs and symptoms
Infectious tenosynovitis occurs between 2.5% and 9.4% of all hand infections. Kanavels cardinal signs is used to diagnose infectious tenosynovitis. They are: tenderness to touch along the flexor aspect of the finger, fusiform enlargement of the affected finger, the finger being held in slight flexion at rest, and severe pain with passive extension. Fever may also be present but is uncommon. Pathogenesis
Infectious tenosynovitis is the infection of closed synovial sheaths in the flexor tendons of the fingers. It is usually caused by trauma, but bacteria can spread from other sites of the body. Although tenosynovitis usually affects the flexor tendon of the fingers, the disease can also affect the extensor tendons occasionally. The clinical presentation is therefore as acute infection following trauma. The infection can be mono- or polymicrobial and can vary depending on the nature of the trauma. The most common pathogenic agent is Staphylococcus aureus introduced from the skin. Other bacteria linked to infectious tenosynovitis include Pasteurella multocida (associated with animal bites), Eikenella spp. (associated with IV drug use), and Mycobacterium marinum (associated with wounds exposed to fresh or salt water). Additionally, sexually active patients are at risk for hematogenous spread due to Neisseria gonorrhoeae (see infectious arthritis).
This should alleviate the defect caused by a faulty gene or slow the progression of the disease. A major obstacle has been the delivery of genes to the appropriate cell, tissue, and organ affected by the disorder. Researchers have investigated how they can introduce a gene into the potentially trillions of cells that carry the defective copy. Finding an answer to this has been a roadblock between understanding the genetic disorder and correcting the genetic disorder. Epidemiology
Around 1 in 50 people are affected by a known single-gene disorder, while around 1 in 263 are affected by a chromosomal disorder. Around 65% of people have some kind of health problem as a result of congenital genetic mutations. Due to the significantly large number of genetic disorders, approximately 1 in 21 people are affected by a genetic disorder classified as "rare" (usually defined as affecting less than 1 in 2,000 people). Most genetic disorders are rare in themselves. There are well over 6,000 known genetic disorders, and new genetic disorders are constantly being described in medical literature. History
The earliest known genetic condition in a hominid was in the fossil species Paranthropus robustus, with over a third of individuals displaying amelogenesis imperfecta.