Alpers disease is also known as progressive neuronal degeneration of childhood with liver disease (PNDC) or, 'Alpers-Huttenlocher syndrome.' It is a rare, autosomal recessive disorder seen in infants and young children. The disease is classified not only as a prion disease but as a, 'mitochondrial encephalomyopathy,' and therefore is associated with the mitochondrial genome. The symptoms of Alpers disease include:
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 meaning two copies of the defective gene is required for active disease, a single copy conveys carrier status. Alpers' disease is caused by certain genetic mutations in the POLG gene.
Alpers disease is an autosomal recessive disorder. What this means is that both parents are carriers of the disease. The disease is due to more than one cause. Some instances are inherited as autosomal recessive traits with both parents appearing average, yet carrying one Alpers gene and each of their children experiencing a 1 in 4 risk of receiving both of the parents Alpers genes and of experiencing the symptoms of the disease.
Other instances of Alpers disease are disorders of oxidative phosphorylation, to include mitochondrial DNA depletion syndromes. Phosphorylation is the addition of phosphate to an organic compound such as the addition of phosphate to adenosine diphosphate (ADP) to form adenosine triphosphate (ATP), or the addition of phosphate to glucose to produce glucose monophosphate, through the action of enzymes known as, 'phosphotransferases,' or, 'kinases.'
Human beings have approximately 30 to 40,000 different genes, each of which has a function in making an individual person. The genes are arranged in pairs, one pair from each parent, on 23 chromosomes. Inevitably, some of these genes are faulty - an average gene may overcome a faulty one. Yet if both genes in the pair are faulty, the genetic instructions are unable to work.
The majority of people carry different faulty genes, yet in Alpers disease and other recessive conditions, parents - while healthy themselves, carry the same faulty genes and risk passing them on to their children. Each pregnancy carries a 25% chance of the child being affected. A child may or may not have shown some developmental delay before the onset of the main disease symptoms, which commonly happen within the first few years of life. Something this may involve initially is a loss of previously learned skills and/or a sudden onset of seizures which are usually very hard to control.
The combination of the severe epilepsy and the on-going brain disease, which is causing the seizures, leads to increasing loss of awareness and skills. An affected infant often times develops some physical stiffness and subtle involuntary movements, particularly of their feet, hands, face and head. The condition is not painful and the child will be unaware of what is happening.
The course of the disease is often times rapid and eventually the combination of the disease affecting the child's brain and increasing physical weakness becomes too great to sustain life. Death usually happens within a year. Parents and caregivers will be aware of the child's increasing fragility and death is often fairly peaceful and expected when the time comes. Rarely, older children and teenagers might develop a seemingly similar condition called, 'Juvenile Alpers Disease,' whose course may be more extended, possibly over a number of years. Other names for Alpers disease include the following:
Treating Alpers Disease
While there is no form of treatment available at this time that can stop the disease, every effort is made to treat the symptoms the child is experiencing. Medications are administered in an attempt to:
Sedative medications may be administered if needed. Feeding may be assisted. Physiotherapists and others can advise parents on seating, positioning and exercising the limbs of the affected child to maintain their comfort. While not scientifically proven, a number of children gain some symptomatic relief from some of the therapies, such as massage and cranial osteopathy.
At this time, there is no cure for Alpers disease and no way to slow the progression of the disease. Treatment is symptomatic and supportive. Anticonvulsants might be administered to treat seizures, but at times the seizures fail to respond well to therapy - even at high dosages. Due to this, the benefit of seizure control should be weighed against what might be excessive sedation from the anticonvulsant. Valproate should not be administered because it may increase the risk of liver failure. Physical therapy might help to relieve spasticity and to increase or maintain muscle tone.
Alpers Disease Prognosis
The prognosis for people with Alpers disease is a poor one. People with the disease usually die within their first decade of life. Continuous and unrelenting seizures often times lead to the person's death. Cardio-respiratory failure due to spinal cord, brain and nerve involvement may also happen. Research on gene-linked neurodegenerative disorders such as Alpers disease is being pursued. The goals of the research are to increase scientific understanding of the disorders and to find ways to treat, prevent and cure them.