Diagnostics and Treatment of Neuronal Ceroid Lipofuscinosis Type 2: Literature Review

Neuronal ceroid lipofuscinosis is a group of rare heredltary diseases with an incidence rate of 0.15 in 100 000 to 9 in 100 000. The disease is caused by mutations in CLN genes, which code various proteins - lyzosomal enzymes, transmembrane lyzosomal proteins, endoplasmic reticulum proteins, potassium, chlo­ride channels in lysosomes and ATPase. Neuronal ceroid lipofuscinosis type 2 is caused by a mutation in CLN2 gene, coding tripeptidyl-peptidase 1. This mutation reduces the concentration of the enzyme resulting in accumulation of lipopigment in lysosomes. The disease damages mainly cerebrum and cerebellum. The disease manifests in second - fourth year of life. Main symptoms of the disease are seizures and/or ataxia, worsening of motor, language and cognitive functions and blindness. The gold standard for diagnostics of neuronal lipofuscinosis type 2 is identification of reduced tripeptidyl-pepti­dase 1 activity and CLN2 mutation in both alleles of the gene. The disease can also be suspected by discovering photoparoxysmal response to photostimulation in electroencephalogram, intracellular deposits in skin biopsy demonstrated by electron microscopy, retinal degeneration observed during ophtalmoscopy and cerebellar atrophy and hyperintense signal in posterior white matter in brain magnetic resonance tomography. Early diagnosis of the disease allows timely treatment with enzyme replacement therapy - cerliponase alpha, slowing progression of the disease. Symptomatic treatment is also important - adequate control of seizures, treatment of motor dysfunction, preservation of speech and communication, pain control, protection of gastrointestinal tract and respiratory system, maintenance of sleep quality, treatment of behavior disorders, family support and quality of life support at the end of life.