Tárolási betegségek, neuronális ceroid lipofuszcinózis

Abstract

Background: Storage diseases are inherited neurodegenerative diseases which affect humans and several animal species including dogs and cats. These disorders are caused by deficient function or decreased activity of lysosomal enzymes and even defective transport of these enzymes or their substrates. These diseases often manifest in different neurological signs in young pure breed animals and in most cases result in their premature death. Some forms of storage diseases also exist with late-onset clinical signs. Neuronal ceroid lipofuscinosis (NCL) is one of the most frequently seen lysosomal storage disorders that manifests in adulthood with progressive movement derangement. Objectives: Examine the clinical appearance of neuronal ceroid lipofuscinosis in American Staffordshire Terriers. Materials and Methods: Eight patients with clinical symptoms that were all homozygous for NCL allele, justified by genetic test were selected to the study. Symptoms were evaluated by clinical examination and/or detailed information from the owners were collected. Results and Discussion: The onset of signs in dogs examined was between 2 and 6 years of age. First signs were transient head tilt and uncoordinated movements, which occurred during walk and trot and worsened with excitement. Later dysmetria, truncal ataxia, loss of balance, falling over to their sides were seen. Progressive worsening of the movement ability of these dogs and ongoing loss of their ambulation capability usually lead to euthanasia well before their life expectation. Supportive and supplementary treatments by the owners did not result in improvement, maybe slowed the progression of the disease. Specific newer therapies from human medicine (enzyme replacement therapy, substrate deprivation therapy, bone marrow transplantation, stem cell therapy, gene therapy) presumably will not get into the veterinary practice because of their high costs. Currently the only solution of this disease would be the elimination of the mutant gene which could be achieved by stricter breeding practices.