Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotten or decaying fish. As this compound builds up in the body, READ MORE

Triosephosphate isomerase deficiency is a disorder characterized by a shortage of red blood cells (anemia), movement problems, increased susceptibility to infection, and muscle weakness that can affect breathing and heart function. The anemia in this READ MORE

Triple A syndrome, also called Allgrove syndrome, is an inherited condition that gets its name from three specific features: achalasia, adrenal insufficiency, and alacrima. Most people with triple A syndrome have all three of these features, although READ MORE

Trisomy 13, also called Patau syndrome, is a chromosomal condition associated with severe intellectual disability and physical abnormalities in many parts of the body. Individuals with trisomy 13 often have heart defects, brain or spinal cord abnorma READ MORE

Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Af READ MORE

Trisomy X, also called triple X syndrome or 47,XXX, is characterized by the presence of an additional X chromosome in each of a female's cells. Although females with this condition may be taller than average, this chromosomal change typically causes READ MORE

TRNT1 deficiency is a condition that affects many body systems. Its signs and symptoms can involve blood cells, the immune system, the eyes, and the nervous system. The severity of the signs and symptoms vary widely. A common feature of TRNT1 deficie READ MORE

Troyer syndrome is a type of hereditary spastic paraplegia, also called hereditary spastic paraparesis. Hereditary spastic paraplegias are a group of genetic disorders characterized by progressive stiffness (spasticity) and weakness of the leg muscle READ MORE

TUBB4A -related leukodystrophy is a disorder that affects the nervous system. Leukodystrophies are conditions that involve abnormalities of the nervous system's white matter, which consists of nerve fibers covered by a fatty substance called myelin. READ MORE

Tuberous sclerosis complex is a genetic disorder characterized by the growth of numerous noncancerous (benign) tumors in many parts of the body. These tumors can occur in the brain, kidneys, heart, skin, and other organs, in some cases leading to sig READ MORE

Tubular aggregate myopathy is a disorder that primarily affects the skeletal muscles, which are muscles the body uses for movement. This disorder causes muscle pain, cramping, or weakness that begins in childhood and worsens over time. The muscles of READ MORE

Tumor necrosis factor receptor-associated periodic syndrome (commonly known as TRAPS) is a condition characterized by recurrent episodes of fever. These fevers typically last about 3 weeks but can last from a few days to a few months. The frequency o READ MORE