Differences in risk factors for dementia with neurodegenerative traits and for vascular dementia

In 229 patients with dementia and in 144 control subjects, polymorphisms of apolipoprotein E (ApoE), low-density-lipoprotein (LDL)-receptor-related protein, alpha(2)-macroglobulin, interleukin (IL) 1beta, angiotensin-converting enzyme and of methylene tetrahydrofolate reductase genes were investigated. In plasma, antibodies against Chlamydia pneumoniae and lipids were determined. Dementia was classified as probable Alzheimer's disease (AD), probable dementia of vascular origin (VaD) and mixed dementia (MD). An association of the disease with ApoE and IL-1beta polymorphism and increased levels of LDL cholesterol were observed in AD and in MD but not in VaD.

[Clinical picture of spinocerebellar ataxia type I (SCA1)]

Spinocerebellar ataxia is a group of diseases with autosomal dominant inheritance heterogenous both clinically and genetically. So called dynamic mutations underlie most these nosological units. The clinical patterns of various SCA types have not yet been defined completely. The purpose of the present report was description of the typical symptoms and signs of type 1 SCA. Seventeen patients from 13 families (M-2, F-15) were studied clinically in detail. The diagnosis was confirmed by DNA analysis. The assessment included neurological status, cognitive functions, the results of EEG, EMG, SEP, VEP, BAER and MRI examinations. The pedigrees indicated autosomal dominant inheritance pattern. The mean age at onset was 35.5 +/- 6.8 years (range 23-45 years) and it suggested negative correlation with the number of CAG repetitions. Cerebellar syndrome limb and truncal, ataxia and dysarthria was present in all cases. Six patients had nystagmus, 3 had slow saccades, 2 had gaze limitation upward, and lateral and 6 had dysphagia. Signs of pyramidal system involvement were found in 10 cases, one had athetotic movements, one had orthostatic hypotension. Two patients had dementia features, 9 had some decline of intellectual functions, mainly with difficulties of memorization, learning and concentration. In 16 cases MRI demonstrated vermis atrophy and atrophy of cerebellar hemispheres, 14 had fourth ventricle dilatation, 8 had flattening of pons base, 8 had narrowing of cervical spinal cord, 8 had dilated CSF spaces over frontal lobes and in 6 cases lateral ventricles were dilated. Electrophysiological peripheral nervous system investigations showed in 16 cases long-standing damage to the motor and sensory peripheral neurons at the level of nerve trunks, more pronounced in sensory nerves. In 13 cases peripheral neuron damage was subclinical. SEP showed in all patients disturbed function of ascending sensory pathways at peripheral and spinocortical levels.

Familial defective apolipoprotein B-100 in a group of hypercholesterolaemic patients in Poland. Identification of a new mutation Thr3492Ile in the apolipoprotein B gene

The prevalence of the familial defective apolipoprotein B-100 (FDB) Arg3500Gln mutation in 525 unrelated hypercholesterolaemic Polish subjects was evaluated. DNA samples were screened for FDB mutation using SSCP method. Presence of mutation was confirmed using a mismatch MspI PCR strategy. Plasma lipid levels and clinical characteristics of 13 patients identified as carriers of the mutation and of their 23 affected relatives were analysed and compared with non-affected ones. In the affected individuals a variable expression of lipid concentrations and of atherosclerosis symptoms were observed. The prevalence of FDB Arg3500Gln mutation in hypercholesterolaemic Polish subjects (3.7%) seems to be similar to the frequency reported in other Caucasian hypercholesterolaemic populations. The estimated prevalence of the mutation in general Polish population is relatively high being 1/250. The same haplotype at the apoB locus in the carriers of this mutation in Poland as in other populations from Western Europe suggests its common origin. In one hypercholesterolaemic subject a non-hitherto described mutation was identified. It consisted in C-->T transition in apoB codon 3492 leading to threonine to isoleucine substitution in 3492 position of apoB gene (Thr3492Ile).

[Detecting carriers of a deletion in the dystrophin gene in families with a single case of Duchenne/Becker muscular dystrophy]

A search for female mutation carriers was performed in 40 families with an isolated case of Duchenne/Becker muscular dystrophy due to a deletion in the dystrophin gene. Intragenic restriction sites and microsatellite sequences (CA repeats) were analysed in females possible carriers of the deletion. Application of this approach enabled us the detection of the deletion in 19 females in 9 families and exclusion of the deletion in 41 females in 23 families. The results of DNA analysis in the remaining 8 families were not informative.

[Autosomal dominant spinocerebellar ataxia]

The modern classification is presented based on genetic criteria of the group of degenerative nervous system diseases inherited as autosomal dominant trait and called collectively spinocerebellar ataxia (SCA). They belong mostly to the class of diseases of similar mutation mechanism in which amplification is present of the trinucleotide sequence (CAG)n. Clinical picture and neuropathological changes in various SCA types are compared.

[Juvenile form of Huntington's disease--diagnostic problems]

Variability of clinical manifestation is an important feature of Huntington's disease (HD). It is due to the high instability of CAG sequences within a coding region of IT15 gene. We present five pedigrees in which apart from the adult form of HD the juvenile form of the disease affected some of the patients--as a result of genetic anticipation. Molecular analysis confirmed the well known fact that anticipation, which manifests itself by earlier onset of the disease in the subsequent generations, is strongly correlated with the degree of amplification of (CAG)n repeats in IT15 gene. An interesting feature of the presented data is the fact, that expansion of CAG repeats occurred not only at the paternal but also at the maternal transmission of the mutation. Some children in the presented HD pedigrees presented other neurological disturbances which could be suspected of HD; a molecular analysis revealing normal number of CAG repeats, enabled us to avoid misdiagnosis. The presented data provide evidence that clinical diagnosis of HD, particularly in cases with not very characteristic clinical picture--is not possible without DNA analysis--even in the families undoubtfully affected with the disease.

Erythrocyte glucose-6-phosphate dehydrogenase deficiency in Poland--a study on the 563 and 1311 mutations of the G6PD gene

Studies on the mutation 563T and silent mutation 1311T of the glucose-6-phosphate dehydrogenase (G6PD) gene in Poland were performed in 26 families affected with G6PD deficiency classified-according to WHO-as group 2 G6PD deficiency. Both mutations were found in 19 families, including 17 of Polish origin. Mutation 563T alone was found in 1 Greek female. The frequency of the silent mutation 1311T in Polish unaffected controls was 0.10. It is postulated that at least parts of the Polish (or Middle-Eastern European) and Mediterranean populations are of a common origin.

Structure and evolution of 5S rRNA genes and pseudogenes in the genus Aspergillus

We have cloned and determined the nucleotide sequence of 18 DNA fragments hybridizing to 5S rRNA from two Aspergillus species--A. wentii and A. awamori. Four of the analyzed sequences were pseudogenes. The gene sequences of these two species were very similar and differed from Aspergillus nidulans at both constant and microheterogeneous sites.