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Dystrophinopathy is the commonest form of muscular dystrophy and comprises clinically recognized forms, Duchenne dystrophy and Becker dystrophy. Mutations in the dystrophin gene which consist of large gene deletions (65%), duplications (5%) and point mutations (30%) are responsible for reducing the amount of functional dystrophin protein in skeletal muscle fibres leading to fibre destruction and disease. The aims of this study are to investigate the detection rate, types and distribution of large gene deletions in Malaysian dystrophinopathy patients using the multiplex polymerase chain reaction (MPCR). MPCR of 18 "hot-spot deletion" regions along the dystrophin gene was performed on DNA from 48 muscle biopsy-confirmed cases of dystrophinopathy. A positive detection rate of 58% (28/48) was observed, where 84% (16/19) Indian, 35% (6/17) Chinese and 50% (6/12) Malay ethnic groups showed deletions in their dystrophin genes. The Malaysian Indians appear to have a higher prevalence for large gene deletions compared to the Chinese and Malays. Further analyses of 42 confirmed positive cases (present 28 plus previous 14 cases) by MPCR showed the majority of deletions were in the mid-distal region of the dystrophin gene (81% in exons 45-60). The MPCR is a specific and sensitive method for confirmation of gene deletions responsible for dystrophinopathy. [ABSTRACT FROM AUTHOR]

Introduction: Interactions of different hemoglobin variants with thalassemia alleles can result in various clinical phenotypes. HbE-beta-thalassemia generally manifests with severe anemia where individuals exhibit beta-thalassemia major with regular blood transfusions or beta-thalassemia intermedia with periodic blood transfusions. This study presents a unique Malay family with three beta-globin gene defects-HbE, Hb South Florida, and IVS1-1 (G-->A).Materials and Methods: HbE activates a cryptic splice site that produces non-functional mRNAs. Hb South Florida is a rare beta-hemoglobin variant, and its interactions with other beta-thalassemia alleles have not been reported. IVS1-1 is a Mediterranean mutation that affects mRNA processing giving rise to beta(o)-thalassemia.Results and Discussion: Fifteen mutations along the beta-globin gene complex were analyzed using the amplification refractory mutation system. Hb South Florida was identified by direct sequencing using genomic DNA.Conclusion: The affected child with HbE/IVS1-1 produced a beta-thalassemia major phenotype. Compound heterozygosity for Hb South Florida/IVS1-1 produced a beta-thalassemia carrier phenotype in the mother. [ABSTRACT FROM AUTHOR]

p53gene mutation is not a frequent event in the tumorigenesis of lymphomas and the expression of p53 protein is independent ofp53gene mutations. The present study aimed to investigate mutations in thep53gene in a series of extranodal B-cell lymphomas, and its association with p53 protein expression. A total of 52 cases were graded histologically into Grade 1, Grade 2 and Grade 3 tumors and p53 protein expression was detected using immunohistochemistry. Mutations in thep53gene were analyzed using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and mobility shifts were confirmed by direct sequencing. The tumors comprised 26 (50%) Grade 1, 9 (17%) Grade 2 and 15 (29%) Grade 3. A high proportion of Grade 2 (25%) tumors expressed p53 protein (P = 0.051) and carriedp53gene mutation (33%) (P = 0.218). However, p53 protein expression was not associated withp53gene mutations (P = 0.057). Transversion mutations (88%) were more frequently detected than transition mutations (12%). The present study revealed thatp53gene mutations and p53 protein expression occurred in higher frequencies in Grade 2 tumors, which may be of pathogenetic importance. The high frequency of transversion mutations may reflect the influence of an etiological agent in the tumorigenesis of mucosa-associated lymphoid tissue (MALT lymphoma). [ABSTRACT FROM AUTHOR]