Dwie mutacje w jednym genie dystrofiny

Background and purpose Duchenne/Becker muscular dystrophies (DMD/BMD) lead to progressive irreversible muscle deterioration caused by recessive mutations in the dystrophin encoding gene (Xp21.1). Approximately 60% of mutations are deletions, 10% are duplications and the remaining 30% are point mutations. The aim of the study is to present the rare occurrence of two pathogenic mutations (deletions or duplications) in one allele of the dystrophin gene. Material and methods DNA of patients from 1364 DMD/BMD families was tested. Two techniques – PCR-multiplex and multiplex ligation-dependent probe amplification – were used to search for mutations in the dystrophin gene. Results Deletion was detected in 648 families and duplication was found in 74 families (analysis in progress). In two families, presence of two mutations in one gene was documented – in the first family two deletions were found (exons 45–49 and 60–61), and in the second family two duplications were detected (exons 2–7 and 50–59). One of the deletions disrupted the reading frame, and the other deletion retained the reading frame. Both duplications also retained the reading frame of the gene but in both families the disease took a severe course (DMD). In the family with two duplications prenatal diagnosis was also carried out, and carriership of both mutations was discovered in the female fetus. Conclusions In the analyzed group of DMD/BMD families, the frequency of combined occurrence of two mutations in one gene was 2 per 722 (0.3%). The phenomenon of detected non-contiguous deletions and duplications is presented together with 31 similar cases published so far.Wstęp i cel pracy Dystrofia mięśniowa Duchenne'a/Beckera (DMD/BMD) jest związana z postępującym i nieodwracalnym zanikiem mięśni wywołanym recesywnymi mutacjami w genie dystrofiny (Xp21.1). Szacuje się, że 60% mutacji stanowią delecje, a 10% – duplikacje; pozostałe 30% mutacji ma charakter punktowy. Celem pracy jest przedstawienie rzadkich przypadków współwystąpienia w jednym allelu genu dystrofiny dwóch chorobotwórczych mutacji – delecji lub duplikacji. Materiał i metody Badano DNA pacjentów z 1364 rodzin skierowanych z podejrzeniem DMD lub BMD. Mutacji poszukiwano, używając dwóch technik: PCR-multiplex i MLPA (multiplex ligation-dependent probe amplification). Wyniki W 648 rodzinach wykryto delecję, a w 74 rodzinach – duplikację (badania w toku). W dwóch rodzinach udokumentowano łączne wystąpienie w jednym genie dystrofiny dwóch mutacji – w pierwszej rodzinie w jednym allelu wykryto dwie delecje (eksony 45–49 i 60–61), a w drugiej rodzinie dwie duplikacje (eksony 2–7 i 50–59). Jedna z delecji naruszała fazę odczytu, druga zaś ją zachowywała; obie duplikacje zachowywały fazę odczytu, jednak w obu rodzinach choroba przybierała ostrą postać (DMD). W rodzinie, w której wykryto dwie duplikacje, wykonano diagnostykę prenatalną, stwierdzając u płodu płci żeńskiej nosicielstwo obu mutacji. Wnioski W analizowanej grupie rodzin z delecją lub duplikacją częstość łącznego wystąpienia dwóch mutacji wyniosła 2 na 722 (0,3%). Zjawisko wykrytych nieciągłych delecji i duplikacji przedstawiamy w zestawieniu z opisanymi dotychczas 31 podobnymi przypadkami

MLPA based detection of mutations in the dystrophin gene of 180 Polish families with Duchenne/Becker muscular dystrophy

Duchenne/Becker muscular dystrophy (DMD/BMD) is a recessive, X-linked disorder caused by a mutation in the dystrophin gene. Deletions account for approximately 60–65% of mutations, duplications for 5–10%. The remaining cases are mainly point mutations. According to Monaco theory clinical form of the disease depends on maintaining or disrupting the reading frame. The purpose of the study was to determine frequency and location of deletions and duplications in the dystrophin gene, to determine the compliance between maintaining/disrupting the reading frame and clinical form of the disease and to check the effectiveness of MLPA (multiplex ligation-dependent probe amplification) in the detection of these mutations in hemizygous patients and heterozygous female carriers. The material is composed of combined results of molecular diagnosis carried out in years 2009–2012 in 180 unrelated patients referred with the diagnosis of DMD/BMD tested by use of MLPA. We identified 110 deletions, 22 duplication (in one patient two different duplications were detected) and 2 point mutations. Deletions involved mainly exons 45–54 and 3–21, whereas most duplications involved exons 3–18. The compliance with Monaco theory was 95% for deletions and 76% for duplications. Most of mutations in the dystrophin gene were localized in the hot spots – different for deletions and duplications. MLPA enabled their quick identification, exact localization and determination whether or not they maintained or disrupted the reading frame. MLPA was also effective in detection of deletions and duplications in female carriers

Creative destruction in science

Drawing on the concept of a gale of creative destruction in a capitalistic economy, we argue that initiatives to assess the robustness of findings in the organizational literature should aim to simultaneously test competing ideas operating in the same theoretical space. In other words, replication efforts should seek not just to support or question the original findings, but also to replace them with revised, stronger theories with greater explanatory power. Achieving this will typically require adding new measures, conditions, and subject populations to research designs, in order to carry out conceptual tests of multiple theories in addition to directly replicating the original findings. To illustrate the value of the creative destruction approach for theory pruning in organizational scholarship, we describe recent replication initiatives re-examining culture and work morality, working parents\u2019 reasoning about day care options, and gender discrimination in hiring decisions. Significance statement It is becoming increasingly clear that many, if not most, published research findings across scientific fields are not readily replicable when the same method is repeated. Although extremely valuable, failed replications risk leaving a theoretical void\u2014 reducing confidence the original theoretical prediction is true, but not replacing it with positive evidence in favor of an alternative theory. We introduce the creative destruction approach to replication, which combines theory pruning methods from the field of management with emerging best practices from the open science movement, with the aim of making replications as generative as possible. In effect, we advocate for a Replication 2.0 movement in which the goal shifts from checking on the reliability of past findings to actively engaging in competitive theory testing and theory building. Scientific transparency statement The materials, code, and data for this article are posted publicly on the Open Science Framework, with links provided in the article

Examining the generalizability of research findings from archival data

This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability—for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples