A dystonia that affects the muscles of the hand and sometimes the forearm and only occurs during handwriting. Similar focal dystonias have also been called writer’s cramp, pianist’s cramp, musician’s cramp, and golfer’s cramp.
A genetic disorder involving the metabolism of the amino acid tyrosine characterized by abnormally high levels of tyrosine in blood (hypertyrosinemia) and urine (tyrosinuria). There are several different forms of tyrosinemia. The classic form, tyrosinemia type I, is due to deficiency of an enzyme called fumarylacetoacetic hydrolase, the last enzyme in the tyrosine pathway. Although […]
- Tyrosinemia type I
A metabolic genetic disease characterized by abnormally high levels of amino acid tyrosine in blood (hypertyrosinemia) and urine (tyrosinuria) due to deficiency of an enzyme called fumarylacetoacetic hydrolase, the last enzyme in the tyrosine pathway. Tyrosinemia type I is inherited as an autosomal recessive disorder. The disease causes cirrhosis of the liver before 6 months […]
- Tyrosinemia type II
A metabolic genetic disease due to deficiency of the enzyme tyrosine transaminase. The disease is characterized by the deposition of crystals of tyrosine in the skin and eyes. Thickened areas (keratoses) on the palms and soles become painful and ulcers develop in the cornea. There is often mental retardation in tyrosinemia type II. It is […]
- Tzanck test
The examination of fluid from a bulla (a blister) in search of Tzanck cells characteristic of varicella (chickenpox), herpes zoster, herpes simplex, and pemphigus vulgaris. Named for a Russian dermatologist Arnault Tzanck (1886-1954).
- Tumor, ear
Benign (noncancerous) bumps on the pinna of the ear (the external ear) or within the external ear canal. Most of these lumps and bumps are just harmless cysts and tumors. However, some of the bumps are bony overgrowths (known as exostoses or osteomas). If they are large and interfere with hearing, they can be surgically […]