Within a couple of years, a wheelchair is required for locomotion and within five to ten years, the person is confined to bed and is often tube fed. Valproic acid and zonisamide are first choice anticonvulsants, and the ketogenic diet may be helpful. An autosomal-recessive genetic defect is responsible, which has been tracked down to two genes. The EPM2A gene on chromosome 6q24 was discovered in 1998 and encodes for the protein laforin. It is responsible for 80% of cases. The EPM2B gene on chromosome 6p22.3 was discovered in 2003 and encodes for the protein malin. There may be a third gene of unknown locus. Neuronal ceroid lipofuscinoses
There are various forms of these disorders, each with their own genetic cause and geographical variation, which lead to accumulation of lipopigments (lipofuscin) in the bodys tissues and are inherited in an autosomal-recessive fashion. Onset and symptoms vary with the particular form, but death usually occurs within five to fifteen years. Type I sialidosis
This is an autosomal recessive disorder in which the body is deficient in α-neuraminidase. Myoclonic epilepsy and ataxia due to potassium (K+) channel mutation (MEAK)
MEAK is a form of progressive myoclonus epilepsy that typically begins between the ages of 3 and 15 years (the average of onset is 10 years). The first symptoms may include ataxia and myoclonus (unsteadiness and difficulty coordinating movements), along with generalized tonic-clonic ("grand mal") seizures. Individuals with MEAK typically do not experience developmental delays.
However, the dosage used in the Phase III trial may have been too low to be efficacious.A Phase II study with maribavir demonstrated that prophylaxis with maribavir displayed strong antiviral activity, as measured by statistically significant reduction in the rate of reactivation of CMV in recipients of hematopoietic stem cell/bone marrow transplants. In an intent-to-treat analysis of the first 100 days after the transplant, the number of subjects who required pre-emptive anti-CMV therapy was statistically significantly reduced with maribavir compared to placebo.ViroPharma conducted a Phase III clinical study to evaluate the prophylactic use for the prevention of cytomegalovirus disease in recipients of allogeneic stem cell transplant patients. In February 2009, ViroPharma announced that the Phase III study failed to achieve its goal, showing no significant difference between maribavir and a placebo at reducing the rate at which CMV DNA levels were detected in patients.The safety and efficacy of maribavir were evaluated in a Phase III, multicenter, open-label, active-controlled trial that compared maribavir with a treatment assigned by a researcher running the study, which could include one or two of the following antivirals used to treat cytomegalovirus: ganciclovir, valganciclovir, foscarnet, or cidofovir. In the study, 352 transplant recipients with cytomegalovirus infections who did not respond (with or without resistance) to treatment randomly received maribavir or treatment assigned by a researcher for up to eight weeks. The study compared the two groups plasma cytomegalovirus DNA concentration levels at the end of the studys eighth week, with efficacy defined as having a level below what is measurable.