Analytical parameters and validation of homopolymer detection in a pyrosequencing-based next generation sequencing system

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The Effect of Small Molecules on Sterol Homeostasis: Measuring 7-Dehydrocholesterol in Dhcr7-Deficient Neuro2a Cells and Human Fibroblasts

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A koleszterin-bioszintézis veleszületett zavara: a Smith–Lemli–Opitz-szindróma

Absztrakt A Smith–Lemli–Opitz-szindróma monogénes, autoszomális recesszív módon öröklődő, mentális retardációval járó többszörös malformatiós szindróma. A kórkép kialakulását a koleszterin-bioszintézis utolsó lépését katalizáló enzim, a 7-dehidrokoleszterin-reduktáz defektusa okozza. A szerzők a nemzetközi irodalom áttekintésével a szindróma patofiziológiájáról, epidemiológiai vonatkozásairól, klinikai megjelenéséről (tünetek, intellektus, fejlődés, életkori sajátosságok), diagnosztikájáról és kezeléséről adnak áttekintést. 2004 óta Magyarországon 14 beteg került felismerésre, amely a becsült incidenciaadatok alapján a kórkép jelentős aluldiagnosztizáltságára utal. A 7-dehidrokoleszterin-reduktáz enzim elégtelen működése miatt a vérben és a szövetekben alacsony koleszterin- és magas 7-dehidrokoleszterin-koncentráció mérhető, amely utóbbi kimutatása szükséges a diagnózis felállításához. Molekuláris genetikai vizsgálattal lehetséges a kóroki mutációk azonosítása és a praenatalis diagnosztika. A klinikai kép rendkívül változatos, a leggyakoribb tünet a 2–3. lábujjak kötőszövetes összenövése. A jelenlegi terápia a koleszterin pótlása, azonban a legújabb eredmények a 7-dehidrokoleszterinből keletkező oxidatív származékok kóroki szerepére utalnak, és ez a megfigyelés az antioxidánsok potenciális terápiás hatékonyságát veti fel. Orv. Hetil., 2015, 156(42), 1695–1702

Vulnerability of DHCR7+/- mutation carriers to aripiprazole and trazodone exposure

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An Ultra-Rare Manifestation of an X-Linked Recessive Disorder: Duchenne Muscular Dystrophy in a Female Patient

Duchenne muscular dystrophy (DMD) is the most common inherited muscle dystrophy. Patients are characterized by muscle weakness, gross motor delay, and elevated serum creatinine kinase (CK) levels. The disease is caused by mutations in the DMD gene located on the X chromosome. Due to the X-linked recessive inheritance pattern, DMD most commonly affects males, who are generally diagnosed between the age of 3–5 years. Here we present an ultra-rare manifestation of DMD in a female patient. Cytogenetic examination showed that she has a t(X;10)(p21.1;p12.1) translocation, which turned out to affect the DMD gene with one of the breakpoints located in exon 54 (detected by genome sequencing). The X-inactivation test revealed skewed X-inactivation (ratio 99:1). Muscle histology and dystrophin immunohistochemistry showed severe dystrophic changes and highly reduced dystrophin expression, respectively. These results, in accordance with the clinical picture and a highly elevated serum CK, led to the diagnosis of DMD. In conclusion, although in very rare cases, DMD can manifest in female patients as well. In this case, a balanced X-autosome reciprocal translocation disrupts the DMD gene and skewed X-inactivation leads to the manifestation of the DMD phenotype

Genetic counselling legislation and practice in cancer in EU Member States

Background: Somatic and germline genetic alterations are significant drivers of cancer. Increasing integration of new technologies which profile these alterations requires timely, equitable and high-quality genetic counselling to facilitate accurate diagnoses and informed decision-making by patients and their families in preventive and clinical settings. This article aims to provide an overview of genetic counselling legislation and practice across European Union (EU) Member States to serve as a foundation for future European recommendations and action. Methods: National legislative databases of all 27 Member States were searched using terms relevant to genetic counselling, translated as appropriate. Interviews with relevant experts from each Member State were conducted to validate legislative search results and provide detailed insights into genetic counselling practice in each country. Results: Genetic counselling is included in national legislative documents of 22 of 27 Member States, with substantial variation in legal mechanisms and prescribed details (i.e. the ‘who, what, when and where’ of counselling). Practice is similarly varied. Workforce capacity (25 of 27 Member States) and genetic literacy (all Member States) were common reported barriers. Recognition and/or better integration of genetic counsellors and updated legislation and were most commonly noted as the ‘most important change’ which would improve practice. Conclusions: This review highlights substantial variability in genetic counselling across EU Member States, as well as common barriers notwithstanding this variation. Future recommendations and action should focus on addressing literacy and capacity challenges through legislative, regulatory and/or strategic approaches at EU, national, regional and/or local levels.</p

Interfering effect of maternal cell contamination on invasive prenatal molecular genetic testing

Objective: Fetal samples obtained by invasive techniques are prone to maternal cellcontamination (MCC), which may lead to false genotyping results. Our aim was todetermine 3 molecular genetic tests' sensitivity to MCC.Method: By mixing experiments, 1%, 5%, 10%, 20%, 30%, and 40% MCC was simulated,and significant MCC levels were determined for Sanger DNA sequencing, multiplexligation?dependent probe amplification (MLPA), and pyrosequencing, a nextgenerationsequencing method.Results: For Sanger sequencing, the limit of sensitivity to MCC was 5% to 30%. ForMLPA, a higher proportion of MCC (?40%) was shown to lead to diagnostic uncertainty.In contrast, pyrosequencing proved to be very sensitive to MCC, detecting aproportion as low as 1%.Conclusion: In the case of Sanger sequencing, sensitivity to MCC was variable,while for MLPA, only high levels of MCC proved to be significant. Although thenext?generation sequencing method was sensitive to low?level MCC, if MCC level isdetermined in parallel, accurate quantification of allelic ratios can help to interpretthe diagnostic results. Knowledge of significant MCC levels allows correct prenataldiagnosis even if samples are not purely of fetal origin and repeated sampling canbe avoided in many of the cases

Cytogenetic Investigation of Infertile Patients in Hungary: A 10-Year Retrospective Study

Chromosome abnormalities play a crucial role in reproductive failure. The presence of numerical or structural aberrations may induce recurrent pregnancy loss or primary infertility. The main purpose of our study was to determine the types and frequency of chromosomal aberrations in infertile patients and to compare the frequency of structural aberrations to a control group. Karyotyping was performed in 1489 men and 780 women diagnosed with reproductive failure between 2010 and 2020. The control group included 869 male and 1160 female patients having cytogenetic evaluations for reasons other than infertility. Sex chromosomal aberrations were detected in 33/1489 (2.22%) infertile men and 3/780 (0.38%) infertile women. Structural abnormalities (e.g., translocation, inversion) were observed in 89/1489 (5.98%) infertile men and 58/780 (7.44%) infertile women. The control population showed structural chromosomal abnormalities in 27/869 (3.11%) men and 39/1160 (3.36%) women. There were significant differences in the prevalence of single-cell translocations between infertile individuals (males: 3.5%; females: 3.46%) and control patients (males: 0.46%; females: 0.7%). In summary, this is the first report of cytogenetic alterations in infertile patients in Hungary. The types of chromosomal abnormalities were comparable to previously published data. The prevalence of less-studied single-cell translocations was significantly higher in infertile patients than in the control population, supporting an earlier suggestion that these aberrations may be causally related to infertility