Alpers' disease
Encyclopedia
Alpers' disease, also called Alpers' syndrome, progressive sclerosing poliodystrophy, and progressive infantile poliodystrophy, is a progressive degenerative disease of the central nervous system
that occurs mostly in infants and children. It is an autosomal recessive disorder that is sometimes seen in siblings. Alpers' disease is caused by certain genetic mutations in the POLG
gene.
s and failure to meet meaningful developmental milestones, usually occur in infancy, after the first year of life, but sometimes as late as the fifth year. Primary symptoms of the disease are developmental delay, progressive mental retardation
, hypotonia (low muscle tone), spasticity (stiffness of the limbs) possibly leading to quadriplegia
, and progressive dementia
. Seizures may include epilepsia partialis continua
, a type of seizure that consists of repeated myoclonic (muscle) jerks. Optic
atrophy may also occur, often leading to blindness
. Deafness may also occur. And, although physical signs of chronic liver
dysfunction may not be present, many patients suffer liver impairment leading to liver failure. While some researchers believe that Alpers' disease is caused by an underlying mitochondrial metabolic defect of POLG
, no consistent defect has been identified. Pathologically
, there is status spongiosus of the cerebral grey matter.
s may be used to treat the seizures. However, caution should be used when selecting valproate as therapy since it may increase the risk of liver failure. Physical therapy may help to relieve spasticity and maintain or increase muscle tone.
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
that occurs mostly in infants and children. It is an autosomal recessive disorder that is sometimes seen in siblings. Alpers' disease is caused by certain genetic mutations in the POLG
POLG
DNA polymerase subunit gamma is an enzyme that in humans is encoded by the POLG gene.-Functions:POLG is the gene that codes for the catalytic subunit of the mitochondrial DNA polymerase, called DNA polymerase gamma . The human POLG cDNA and gene were originally cloned mapped to chromosome 15,...
gene.
Presentation
Alpers' formal name is Alpers-Huttenlocher syndrome (AHS). First signs of the disease, which include intractable seizureSeizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
s and failure to meet meaningful developmental milestones, usually occur in infancy, after the first year of life, but sometimes as late as the fifth year. Primary symptoms of the disease are developmental delay, progressive mental retardation
Mental retardation
Mental retardation is a generalized disorder appearing before adulthood, characterized by significantly impaired cognitive functioning and deficits in two or more adaptive behaviors...
, hypotonia (low muscle tone), spasticity (stiffness of the limbs) possibly leading to quadriplegia
Quadriplegia
Tetraplegia, also known as quadriplegia, is paralysis caused by illness or injury to a human that results in the partial or total loss of use of all their limbs and torso; paraplegia is similar but does not affect the arms...
, and progressive dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
. Seizures may include epilepsia partialis continua
Epilepsia partialis continua
Epilepsia partialis continua is a rare type of brain disorder in which a patient experiences recurrent motor epileptic seizures that are focal , and recur every few seconds or minutes for extended periods .-Presentation:During these seizures, there is repetitive focal myoclonus or Jacksonian...
, a type of seizure that consists of repeated myoclonic (muscle) jerks. Optic
Optic nerve
The optic nerve, also called cranial nerve 2, transmits visual information from the retina to the brain. Derived from the embryonic retinal ganglion cell, a diverticulum located in the diencephalon, the optic nerve doesn't regenerate after transection.-Anatomy:The optic nerve is the second of...
atrophy may also occur, often leading to blindness
Blindness
Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...
. Deafness may also occur. And, although physical signs of chronic liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
dysfunction may not be present, many patients suffer liver impairment leading to liver failure. While some researchers believe that Alpers' disease is caused by an underlying mitochondrial metabolic defect of POLG
POLG
DNA polymerase subunit gamma is an enzyme that in humans is encoded by the POLG gene.-Functions:POLG is the gene that codes for the catalytic subunit of the mitochondrial DNA polymerase, called DNA polymerase gamma . The human POLG cDNA and gene were originally cloned mapped to chromosome 15,...
, no consistent defect has been identified. Pathologically
Pathology
Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....
, there is status spongiosus of the cerebral grey matter.
Treatment
There is no cure for Alpers' disease and, currently, no way to slow its progression. Treatment is symptomatic and supportive. AnticonvulsantAnticonvulsant
The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...
s may be used to treat the seizures. However, caution should be used when selecting valproate as therapy since it may increase the risk of liver failure. Physical therapy may help to relieve spasticity and maintain or increase muscle tone.
Prognosis
The prognosis for individuals with Alpers' disease is poor. Those with the disease usually die within their first decade of life. Liver failure is usually the cause of death, although cardiorespiratory failure may also occur.External links
- "Alpers' Disease Information Page". (Website). National Institute of Neurological Disorders and Stroke, U.S. National Institutes of Health.
- "Non-Profit Organization". (Website). Dedicated to research and education for mitochondrial diseases
- "The Nicholas Appeal" (Website). Non-charitable trust