Angelman syndrome (AS) is a neurogenic disease, which is clinically characterized mainly by psychomotor retardation, epilepsy, severe speech disorder, ataxia and hyperactivity. AS may be classified into the so called contiguous gene syndrome, where the defect may concern more mutually unrelated and functionally different genes positioned in a close neighborhood. Genetic mechanism, leading to the defect of critical area 15qll-13 is different. Deletion is most frequent (75%), while the other causes include uniparental paternal disomia, mutation of UBE3 gene or mutation of genes in the imprinting center. The authors describe the čase of a child, whose clinical course suggested presence of AS. FISH method excluded microdeletion. AS was confirmed by DNA analysis, which was tested in the child and the parents by methylation-sensitive PCR (MS-PCR) and STR analysis with an application of di-, tetra- and pentanucleotide repetitions. The presence of a single parental allele of chromosome 15 (uniparental paternal disomia) confirmed clinically suspected Angelman syndrome.

        Key words: Angelman syndrome, uniparental paternal disomia