Parkin (PARK 2) mutations are rare in Czech patients with early-onset Parkinson's disease.

OBJECTIVE: The aim of the study is to determine the frequency of parkin allelic variants in Czech early-onset Parkinson's disease patients and healthy controls. METHODS: A total of 70 early-onset Parkinson's disease patients (age at onset ≤40 years) and 75 controls were screened for the sequence variants and exon rearrangements in the parkin gene. RESULTS: Parkin mutations were identified in five patients (7.1%): the p.R334C point mutation was present in one patient, four patients had exon deletions. The detected mutations were observed in the heterozygous state except one homozygous deletion of the exon 4. No mutations were obtained in control subjects. A novel sequence variant p.V380I (c.1138G>A) was identified in one control. Non-pathogenic polymorphisms p.S167N and p.D394N were seen in similar percentage in patients and controls, polymorphism p.V380L was almost twice as frequent in controls as in patients. CONCLUSIONS: Our study contributes to the growing body of evidence on the low frequency of the parkin mutations in the early-onset Parkinson's disease suggesting the potential role of other genes in the pathogenesis of the disease.

[Molecular pathology of pulmonary carcinomas]. / Molekulární patologie plicních karcinomu

The group of non-small cell lung carcinomas includes tumors that are variable at the clinical, histopathological and molecular levels. Advances in the understanding of molecular pathology of lung adenocarcinomas in particular has led to changes in their histopathological classification and treatment. Patients diagnosed with lung adenocarcinoma harboring specific mutations benefit from the administration of specific targeted therapy. Therefore, pathologists closely involved in the diagnostics of lung tumors significantly contribute to the diagnostic-therapeutical algorithm. Analysis of EGFR gene mutations in lung adenocarcinomas is already routinely performed and the presence of activating mutations in EGFR is the main indication for the administration of tyrosinkinase inhibitors. Besides EGFR mutations, EML4-ALK rearrangement is also being analysed and there is potential in analysing BRAF mutations as well. The aim of this review is to summarize the role of the most relevant molecules that also serve as the therapeutic target for practicing pathologists.

Gerstmann-Sträussler-Scheinker syndrome with the P102L pathogenic mutation presenting as familial Creutzfeldt-Jakob disease: a case report and review of the literature.

Gerstmann-Sträussler-Scheinker syndrome is a rare autosomal dominant disease caused by a mutation in the prion gene, usually manifesting as progressive ataxia with late cognitive decline. A 44-year-old woman with a positive family history developed early personality and behavior changes, followed by paresthesias and ataxia, later associated with memory problems, pyramidal signs, anosognosia and very late myoclonus, spasticity, and severe dysexecutive impairment. Magnetic resonance showed caudate, mesio-frontal, and insular hyper-intensities, electroencephalography revealed generalized triphasic periodic complexes. A pathogenic P102L mutation in the prion gene was detected. Our case differed from classical Gerstmann-Sträussler-Scheinker syndrome by rapid progression, severe dementia, abnormal electroencephalography and magnetic resonance findings, which were highly suggestive of familial Creutzfeldt-Jakob disease.

[KRAS mutation testing in therapeutic algorithm for treatment of metastatic colorectal carcinoma]. / Vysetrení mutacního statutu genu KRAS jako soucást algoritmu lécby metastatického kolorektálního karcinomu.

Targeted therapy has become an integral part of treatment procedures of malignant tumors. Colorectal carcinomas are frequently targeted with monoclonal anti-EGFR antibodies (cetuximab and panitumumab). Activating somatic mutations in codons 12 and 13 of the exon 2 of KRAS gene are considered negative predictive factors of response to anti-EGFR therapy in patients with metastatic colorectal cancer. In the Czech Republic, evaluation of mutational status of KRAS gene is performed in several referral laboratories. In 2009, these laboratories performed 2580 tests of the KRAS mutational status--out of these, 60.2% cases reported non-mutated, wild-type KRAS. In one of the referral laboratories, we demonstrate the logistics of KRAS testing procedure. Stratification of patients with metastatic colorectal tumors based on their KRAS mutational status has evolved to a standard procedure. Laboratories performing these methods shall therefore adhere to the recommendations of the professional and accredited societies.

Parkin mutations and phenotypic features in Czech patients with early-onset Parkinson's disease.

OBJECTIVES: Mutations in several genes such as parkin can be detected in up to 20% of patients with early-onset Parkinson's disease (EOPD). The aim of our study was to determine the frequency of parkin alterations and phenotypic characteristics in Czech EOPD patients. METHODS: A total of 45 EOPD individuals (age at onset <45 years) were phenotyped and screened for parkin mutations. RESULTS: In total, 19 patients (42.2%) were carriers of previously described heterozygous genetic alterations. Parkin mutations (Ex2del, R402C) were identified in two (4.4%) cases, non-pathogenic variant A82E plus polymorphism D394N occurred in one (2.2%) patient and parkin polymorphisms (3x S167N, 1x R334C, 7x V380L, 4x D394N) were found in 15 (34.9%) individuals. Furthermore, the G2019S mutation in the LRRK2 gene was found in one (2.2%) subject. CONCLUSION: The clinical characteristics of our patients correspond to previous descriptions of EOPD phenotype. This is the first report on EOPD-associated genetic alterations among Czech patients. Our results support the hypothesis that single heterozygous parkin variants may act as risk factors for EOPD.

QF-PCR examination of parental and meiotic origin of trisomy 21 in Central and Eastern Europe.

Study of parental/meiotic origin of free trisomy 21 in nuclear families from Russia (70 cases), Ukraine (32 cases), and 22 from Germany revealed maternal nondisjunction in 77.3% (Germany), 93.8% (Ukraine), and 91.4% (Russia), paternal origin in 13.6%, 6.2%, and 8.6%, respectively. Maternal meiosis I errors were found in 84.4% (Ukraine), 77.1% (Russia), paternal origin in 3.1% (Ukraine), 2.9% (Russia). Maternal meiosis II errors occurred in 9.4% and 14.3% and paternal in 3.1% and 5.7% in Ukraine and Russia, respectively. No significant differences were found in maternal/paternal origin among Ukraine, Russia, Germany, and published data from other European regions.