Hyperphosphatemic familial tumoral calcinosis
Hyperostosis hyperphosphatemia syndrome
Type of disease: Rare conditions
Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare condition characterized by higher than normal levels of phospate in the blood (hyperphosphatemia) and abnormal deposits of both phosphate and calcium (calcinosis) in the body’s tissues. Calcinosis most commonly appears from early childhood to early adulthood. Calcinosis occurs just under the skin and typically around the joints such as the hips, elbows and shoulders, but can also show up in the soft tissues of the feet, legs, and hands. Sometimes calcinosis can occur within the blood vessels and brain which can be serious. The deposits grow slowly and vary in size and number among different affected individuals. Larger desposits may affect the function of the joint they develop on and appear to be tumors (tumoral) though they are not tumors and are not cancerous.
Other features of HFTC may include corneal calcification (buildup of calcium around front part of eye), angiod streaks (tiny breaks in the tissue at the back of the eye), inflammation of the long bones (diaphysis), or hyperostosis (excessive bone growth) and occasionally abnormalities of the teeth. Males may also have small accumulations of cholesterol in the testicles which usually is not cause for concern. HFTC is seen most commonly in Middle Eastern and African populations and is inherited in an autosomal recessive manner. This means that a person affected by HFTC has two mutated (changed) copies of a gene, one from each parent. A person with only one mutated gene is called a carrier and usually does not experience any symptoms.
A milder form of HFTC is thought to exist called hyperostosis-hyperphosphatmia syndrome (HHS) and only involves higher levels of phosphate in the blood along with excessive bone growth and lesions on the bone. Talk with a genetic counselor or specialist if you have been diagnosed with HFTC or HHS.