Alpers disease
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 usually seen in infants and young children. Alpers Disease is classified not only as a prion disease but as a "mitochondrial encephalomyopathy" and therefore is associated with the mitochondrial genome. Symptoms include increased muscle tone with exaggerated reflexes (spasticity), seizures, loss of cognitive ability (dementia) and, in many cases, liver disease.
Alpers' disease is an autosomal recessive disorder; this means that both parents are carriers of the disease. Alpers disease is due to more than one cause. Some cases are inherited as autosomal recessive traits with both parents appearing normal but carrying one Alpers gene and each of their children, boys and girls alike, standing a 1 in 4 risk of receiving both of the parental Alpers genes and of suffering from this dread disease.
Other cases of Alpers disease are disorders of oxidative phosphorylation, including mitochondrial DNA depletion syndromes. (Phosphorylation is the addition of phosphate to an organic compound, such as the addition of phosphate to ADP (adenosine diphosphate) to form ATP [adenosine triphosphate] or the addition of phosphate to glucose to produce glucose monophosphate, through the action of enzymes known as phosphotransferases or kinases.)
Human beings have about 30 to 40,000 different genes, each of which has a function in making an individual person. The genes are arranged in pairs (one of the pair from each parent) on 23 chromosomes. Inevitably, some of these genes are faulty; a normal gene can overcome a faulty one, but if both genes in the pair are faulty, the genetic instructions cannot work.
Most people carry different faulty genes but in Alpers Disease (and other recessive conditions) parents, though healthy themselves, carry the same faulty genes, and risk passing them on to their children. Each pregnancy carries a 25 per cent chance of the child being affected. Your child may or may not have shown some developmental delay prior to the onset of the main disease symptoms, which usually occur within the first few years of life; these may initially involve a loss of previously learnt skills and / or a sudden onset of seizures which are usually very difficult to control.
The combination of the severe epilepsy and the on-going brain disease, which is causing the seizures, leads to increasing loss of skills and awareness. The infant often develops some physical stiffness (spasticity) and subtle involuntary movements especially of hands, feet, face and head. The condition is not a painful one and the child will be unaware of what is happening. The course of the disease is usually rapid and eventually the combination of the diseased brain and increasing physical weakness becomes too great to sustain life, and death usually occurs within a year. Parents and carers will be aware of the child’s increasing frailty, and death is usually relatively peaceful and expected when the time comes. Very rarely older children and teenagers may develop an apparently similar condition called Juvenile Alpers’ Disease, whose course may be more protracted, over very many years.
Although there is no treatment yet available that can stop the disease, every effort is made to treat the symptoms. Drugs are given to try to reduce some of the seizures, treat infections and relieve any muscle spasm, pain relief and sedative drugs can be given if required and feeding can be assisted. Physiotherapists and others can advise parents on positioning, seating and exercising the limbs to maintain comfort. Though not scientifically proven, many children gain some symptomatic relief from some of the complementary therapies such as cranial osteopathy and massage. |