Rhabdoid tumor predisposition syndrome (RTPS) is characterized by a high risk of developing cancerous (malignant) growths called rhabdoid tumors. These highly aggressive tumors are called rhabdoid because their cells resemble rhabdomyoblasts, which a READ MORE

Rheumatoid arthritis is a disease that causes chronic inflammation that primarily affects the joints. The most common signs and symptoms are pain, swelling, and stiffness of the joints. This condition frequently affects the hands and feet, although t READ MORE

Rhizomelic chondrodysplasia punctata is a condition that impairs the normal development of many parts of the body. The major features of this disorder include skeletal abnormalities, distinctive facial features, intellectual disability, and respirato READ MORE

Riboflavin transporter deficiency neuronopathy is a disorder that affects nerve cells (neurons). Affected individuals typically have hearing loss caused by nerve damage in the inner ear (sensorineural hearing loss) and signs of damage to other nerves READ MORE

Rigid spine muscular dystrophy (RSMD) is a form of congenital muscular dystrophy. Disorders in this group cause muscle weakness and wasting (atrophy) beginning very early in life. In particular, RSMD involves weakness of the muscles of the torso and READ MORE

Ring chromosome 14 syndrome is a condition characterized by seizures and intellectual disability. Recurrent seizures (epilepsy) develop in infancy or early childhood. In many cases, the seizures are resistant to treatment with anti-epileptic drugs. M READ MORE

Ring chromosome 20 syndrome is a condition that affects the normal development and function of the brain. The most common feature of this condition is recurrent seizures (epilepsy) in childhood. The seizures may occur during the day or at night durin READ MORE

Rippling muscle disease is a condition in which the muscles are unusually sensitive to movement or pressure (irritable). The muscles near the center of the body (proximal muscles) are most affected, especially the thighs. In most people with this con READ MORE

RNAse T2-deficient leukoencephalopathy is a disorder that affects the brain. People with RNAse T2-deficient leukoencephalopathy have neurological problems that become apparent during infancy; the problems generally do not worsen over time (progress). READ MORE

Roberts syndrome is a genetic disorder characterized by limb and facial abnormalities. Affected individuals also grow slowly before and after birth. Mild to severe intellectual impairment occurs in about half of all people with Roberts syndrome. Chil READ MORE

Robinow syndrome is a rare disorder that affects the development of many parts of the body, particularly the skeleton. The types of Robinow syndrome can be distinguished by the severity of their signs and symptoms and by their pattern of inheritance: READ MORE

Romano-Ward syndrome is a condition that causes a disruption of the heart's normal rhythm (arrhythmia). This disorder is a form of long QT syndrome, which is a heart condition that causes the heart (cardiac) muscle to take longer than usual to rechar READ MORE