👤 Naoki Hosen

Lymphoplasmacytic lymphoma (LPL) is a type of indolent B-cell lymphoma typically associated with IgM paraproteinemia and does not require immediate treatment until symptoms appear. However, non-IgM LPL has a higher frequency of extramedullary involvement and requires more aggressive therapy than IgM-LPL. A 51-year-old woman in treatment-free follow-up for LPL with IgG-κ paraproteinemia was referred to our hospital with a chief complaint of right coxalgia. A plain MRI scan showed multiple osteolytic bone lesions, including bilateral femoral incomplete fractures. Similar bone lesions were also detected in the right shoulder joint. Pathological examination of the bilateral femurs and the right shoulder revealed LPL lesions with amyloid deposits. MYD88 L265P gene mutations were confirmed by genetic analysis, and all lesions were considered identical. Ibrutinib plus rituximab therapy was administered, resulting in a partial response sustained to date. Bone involvement and amyloidosis are rare but critical extranodal manifestations of LPL, necessitating careful screening and follow-up even in asymptomatic patients. When these manifestations are suspected, prompt pathological and genetic evaluation is warranted, especially in non-IgM LPL cases. Show less

Hypertrophic cardiomyopathy (HCM) is the most prevalent genetic hereditary cardiomyopathy characterized by sudden cardiac death. Mutations in the MYBPC3 gene are often the most prevalent genetic abnormality in HCM with a prevalence ranging from 20.0 to 42.0%. The mutation spectrum is available for different countries, but such studies are lacking in the Asian population including Bangladeshi patients. A cross-sectional descriptive study was conducted for mutation analysis of the whole MYBPC3 gene on a cohort of 75 HCM Bengali Bangladeshi probands through Next Generation Sequencing at the Genetic Research Lab of Bangabandhu Sheikh Mujib Medical University from 2016 to 2019. The structural and functional impact of the mutations was further analyzed by in silico process. We analyzed the data and found 103 variants in 102 locations in the MYBPC3 gene. Variants were identified in both the coding region and the non-coding region. We found one possibly novel variant in the MYBPC3 gene. The findings of this research will help to develop a genetic database of HCM which will help in the early diagnosis and proper management of HCM patients in Bangladesh. One pathogenic splice donor variant (47356592 C >T) was found in the intronic region. Among the variants in the coding region, one missense mutation was pathogenic (NP₋000247.2: p.Asp770Asn) which was found in seven patients and another one is of conflicting interpretations of pathogenicity (NP₋000247.2: p.Ser217Gly) which was found in two patients. We have identified one in-frame deletion (NP₋000247.2: p.Ala433del) that is possible a novel variant responsible for the development of HCM. Show less