Influence of different spectra of NOTCH3 variants on the clinical phenotype of CADASIL - experience from Slovakia.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary vascular disorder causing ischaemic attacks and strokes in middle-aged adults. Though the clinical spectrum includes some typical symptoms, recognition of the disease, especially at an earlier stage, is very difficult because of the highly variable manifestation and incomplete clinical picture. Characteristic brain MRI findings and the presence of pathogenic variants in the NOTCH3 gene are fundamental for CADASIL diagnosis. In this paper, we provide the first comprehensive report on CADASIL patients from Slovakia. Altogether, we identified 23 different pathogenic variants in 35 unrelated families. In our cohort of patients with clinical suspicion of CADASIL, we found a causal genetic defect and confirmed the diagnosis in 10.2% of cases. We present the case reports with up-to-date unpublished NOTCH3 variants and describe their phenotype-genotype correlation: p.(Cys65Phe), p.(Pro86Leu/Ser502Phe), p.(Arg156*), p.(Cys408Arg), p.(Tyr423Cys), p.(Asp1720His), and p.(Asp1893Thrfs*13). The most frequently described location for pathogenic variants was in exon 4, whereas the most common single variant was p.Arg1076Cys in exon 20. Based on the results of our study, we propose a re-evaluation of the criteria for the selection of patients suitable for NOTCH3 gene analysis. We hereby state that the currently used protocol of a high score requirement is not ideal for assessing molecular analysis, and it will be desirable to be less strict in criteria for genetic testing.

[Nijmegen breakage syndrome in Slovakia]. / Nijmegen breakage syndrom na slovensku.

BACKGROUND: The autosomal recessive Nijmegen breakage syndrome (NBS) is a DNA repair disorder due to a mutation in the NBS1 gene on 8q21. Hyperradiosensitivity and high risk for lymphoreticular malignancy are important reasons for early diagnosis and prevention by avoidance of ionisation. The frequency of NBS heterozygotes of the mutation 657de15, which is predominant in the Slavic population was estimated to be in the range of 1:90-1:314 in different parts of Poland, and 1:128-154 among Czech newborns, born 20 years ago. METHODS AND RESULTS: Lower prevalence of affected homozygotes born in Czechoslovakia in the period 1969- 1992 (24 among 5.2 million newborns corresponds to 1:271000) than expected on the basis of carrier frequency is explained to be due to underdiagnosing because the rate of prenatal lethality in the NBS families is not increased or it is even lower than in the general population. The underdiagnosing of NBS is emphasized also by the mean age at diagnosis (7.5 years) although severe microcephaly is present at birth. The possibility to offer effective prevention of primary and secondary malignancies becomes the motivation for interdisciplinary collaboration with paediatricians, neurologists, immunologists and clinical geneticists. A decrease of the mean age down to 6 months at diagnosis among the 11 newly recognized patients has been achieved in the previous 4 years. The occurrence of homozygotes was relatively higher in Slovakia with 5 million inhabitants (14 patients in 11 families) than in the Czech Republic with a population of 10 million (21 patients in 14 families), and therefore the frequency of NBS heterozygotes was studied among 2996 newborns born in 2002-2003 in 12 maternity hospitals of west, middle and east Slovakia. Surprisingly, only 3 heterozygotes were found. CONCLUSIONS: This discrepancy of heterozygote frequency and the number of homozygotes shows that due to traditional subisolates the population is not in the genetic equilibrium. It explains the high prevalence of alcaptonuria in Slovakia in the middle of last century, which is a rare disorder in other countries.

Trisomy 18 mimicking Smith-Lemli-Opitz syndrome in the immediate neonatal period.

The study describes a dysmorphic newborn infant with life-threating anomaly, later diagnosed as trisomy 18, mimicking Smith-Lemli-Opitz syndrome in the immediate neonatal period. The establishment of the correct diagnosis in the first days of life is very important for the decision-making process, because trisomy 18 has a poor prognosis, and treatment is not instituted, whereas cholesterol supplementation may be of benefit to patients with Smith-Lemli-Opitz syndrome. Ultraviolet spectrophotometry showed very easy and rapid method for differentiation of both syndromes, where gas chromatography/mass spectrometry analysis is not available. (Fig. 2, Ref: 18.)

Variability in kyphomelic dysplasia.

Four infants with kyphomelic dysplasia ascertained from three families demonstrate variability within the syndrome. In the first family, sibling recurrence in female sibs was noted with atypical kyphomelic dysplasias, suggesting autosomal recessive inheritance. In the second family, with a male affected with the 'typical findings' of lethal kyphomelic dysplasia, diagnosis of a skeletal dysplasia was suspected at 29-30 weeks' gestation following US detection of short, bent femurs. In the third family, with a female affected, severe radiographic changes were documented at birth. The clinical course of the disease was mild with almost complete regression of the radiographic findings at the age of 7 years.

Lethal kyphomelic dysplasia.

A lethal form of kyphomelic dysplasia with severe bowing of the long bones of the lower extremities is reported.

[The effect of physical stress on rheological properties of blood]. / Vliv fyzické záteze na reologické vlastnosti krve.

The influence of physical load on blood viscosity was observed in the presented study. Three groups of persons were examined: 23 volleyball and football players, 96 employees of a nuclear power plant, and 49 employees of a coal power plant. The values of blood viscosity and hematocrit were determined in the quiescent state before the load, after the performance of 2W.kg-1, and after the maximum performance obtained at a bicycle ergometer. After the data processing the following results were obtained: The average performance of the trained persons was 40% higher compared to the untrained persons (power plants employees). Blood viscosity was lower before the load in the trained persons, and remained on average by 5% lower also after the maximum load. The total relative increase of the value of blood viscosity caused by the maximum load was however approximately the same in all groups (about 15%). The mean value of blood pressure increased with the increased blood viscosity, and therefore also with the increased physical load. The study contains also mathematical expressions of the observed relations.