Genetic Disorders

Definition Refsum disease is a genetic disorder that affects the metabolism of the fatty acid phytanic acid. When phytanic acid accumulates, it causes a number of progressive problems, including retinitis pigmentosa, peripheral neuropathy, anosmia, deafness, cerebellar ataxia and elevated protein concentrations in the cerebrospinal fluid in the absence of an …

Definition Prader-Willi syndrome is a complex genetic condition that affects many parts of the body. In infancy, this condition is characterized by weak muscle tone (hypotonia), feeding difficulties, poor growth, and delayed development. Beginning in childhood, affected individuals develop an insatiable appetite, which leads to chronic overeating (hyperphagia) and obesity. …

What is Brugada syndrome? Brugada syndrome is a genetic disorder that can causes a dangerous irregular heartbeat. In many cases, a defect in the SCN5A gene causes the genetic form of this condition. When this defect occurs, it may cause a ventricular arrhythmia. This is a type of irregular heartbeat. …

Definition Adrenomyeloneuropathy (AMN) is an inherited condition that affects the spinal cord. It is a form of X-linked adrenoleukodystrophy. On average, people with AMN begin to develop features in the late twenties. Signs and symptoms may include progressive stiffness and weakness of the legs; ataxia; speech difficulties; adrenal insufficiency; sexual …

What is Fabry Disease? Fabry Disease (FD) is a rare genetic disorder caused by a defective gene (the GLA gene) in the body. In most cases, the defect in the gene causes a deficient quantity of the enzyme alpha-galactosidase A. This enzyme is necessary for the daily breakdown (metabolism) of …

What is Becker muscular dystrophy? Becker muscular dystrophy (BMD) is one of nine types of muscular dystrophies, a group of genetic, degenerative diseases primarily affecting voluntary muscles. BMD belongs to a group of dystrophinopathies including Duchenne muscular dystrophy (DMD) and an intermediate form between DMD and BMD. The disease is …

Definition Mitochondrial disease result from failures of the mitochondria, specialized compartments present in every cell of the body (except red blood cells). Mitochondria are responsible for creating more than 90% of the energy needed by the body to sustain life and support organ function. When they fail, less and less …

Gricelli Syndrome – Overview Gricelli syndrome is an inherited condition characterized by unusually light (hypopigmented) skin and light silvery-gray hair starting in infancy. Researchers have identified three types of this disorder, which are distinguished by their genetic cause and pattern of signs and symptoms. Griscelli syndrome type 1 involves severe …