Katarzyna Tońska

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Polymorphisms in mitochondrial DNA (mtDNA) were analyzed in 152 samples from the Polish population using restriction enzymes AvaI, BamHI, HaeII, HpaI and PstI. Additionally, each sample was classified into the appropriate haplogroup. When required, appropriate fragments were sequenced to establish the exact polymorphic sites. We found one new morph for PstI(More)
Human mtDNA is transcribed from both strands, producing polycistronic RNA species that are immediately processed. Discrete RNA units are matured by the addition of nucleotides at their 3' termini: -CCA trinucleotide is added to mt-tRNAs, whilst mt-rRNAs and mt-mRNAs are oligo- or polyadenylated, respectively. The cis-acting elements, enzymes and indeed the(More)
Three mutations in mitochondrial DNA complex I genes are responsible for over 90% of Leber hereditary optic neuropathy (LHON) cases in Europe. A family with two LHON mutations--practically homoplasmic 11778G>A and varying levels of 3460G>A--was found during analysis of Polish patients. DNA and visual acuity was analyzed in four affected brothers and their(More)
Leber hereditary optic neuropathy (LHON), acute or subacute vision loss due to retinal ganglion cell death which in the long run leads to optic nerve atrophy is one of the most widely studied maternally inherited diseases caused by mutations in mitochondrial DNA. Although three common mutations, 11778G>A, 14484T>C or 3460G>A are responsible for over 90% of(More)
UNLABELLED Leigh syndrome (LS), or subacute necrotizing encephalomyelopathy, having relatively homogeneous clinical symptomatology and pattern of neuropathological changes, shows remarkable heterogeneity in biochemical and molecular background. G8363A mitochondrial DNA mutation typical for MERRF syndrome and progressive cardiomyopathy may also be associated(More)
BACKGROUND AND PURPOSE Mitochondrial cytopathies are heterogeneous disorders affecting multiple systems but most commonly involving the skeletal muscle and central nervous system. The variety of symptoms and signs requires biochemical, morphological and genetic evaluation. The results of genetic studies indicate that there is no direct correlation between(More)
BACKGROUND MELAS (mitochondrial myopathy, lactic acidosis and stroke-like episodes) is one of the most common mitochondrial encephalomyopathies. MATERIAL/METHODS We present four children with A3243G MELAS mtDNA mutation and give a summary of clinical MELAS symptoms reported in the literature. Serum lactate elevation, mosaic pattern of COX deficit and(More)
Leber hereditary optic neuropathy (LHON) is a genetic, maternally inherited disease caused by point mutations in the mitochondrial genome. LHON patients present with sudden, painless and usually bilateral loss of vision caused by optic nerve atrophy. The first clinical description of the disease was made by Theodor Leber, a German ophthalmologist, in 1871.(More)
Mutations in NADH dehydrogenase (ND) subunits of complex I lead to mitochondrial encephalomyopathies associated with various phenotypes. This report aims to present the patient’s clinical symptomatology in the context of a very rare 13042G>A de novo mutation and with an emphasis on changing phenotypic expression and pronounced, long-standing response to(More)