X-linked myotubular myopathy is associated with epigenetic alterations and is ameliorated by HDAC inhibition.

X-linked myotubular myopathy (XLMTM) is a fatal neuromuscular disorder caused by loss of function mutations in MTM1. At present, there are no directed therapies for XLMTM, and incomplete understanding of disease pathomechanisms. To address these knowledge gaps, we performed a drug screen in mtm1 mutant zebrafish and identified four positive hits, including valproic acid, which functions as a potent suppressor of the mtm1 zebrafish phenotype via HDAC inhibition.

Natural history of a mouse model of X-linked myotubular myopathy.

X-linked myotubular myopathy (XLMTM) is a severe monogenetic disorder of the skeletal muscle. It is caused by loss-of-expression/function mutations in the myotubularin (MTM1) gene. Much of what is known about the disease, as well as the treatment strategies, has been uncovered through experimentation in pre-clinical models, particularly the Mtm1 gene knockout mouse line (Mtm1 KO).

Incidental findings from cancer next generation sequencing panels.

Next-generation sequencing (NGS) technologies have facilitated multi-gene panel (MGP) testing to detect germline DNA variants in hereditary cancer patients. This sensitive technique can uncover unexpected, non-germline incidental findings indicative of mosaicism, clonal hematopoiesis (CH), or hematologic malignancies. A retrospective chart review was conducted to identify cases of incidental findings from NGS-MGP testing.

A sub-national real-time epidemiological and vaccination database for the COVID-19 pandemic in Canada.

The COVID-19 pandemic has demonstrated the need for real-time, open-access epidemiological information to inform public health decision-making and outbreak control efforts. In Canada, authority for healthcare delivery primarily lies at the provincial and territorial level; however, at the outset of the pandemic no definitive pan-Canadian COVID-19 datasets were available. The COVID-19 Canada Open Data Working Group was created to fill this crucial data gap.

Genetic therapy for congenital myopathies.

Purpose Of Review: There has been an explosion of advancement in the field of genetic therapies. The first gene-based treatments are now in clinical practice, with several additional therapeutic programs in various stages of development. Novel technologies are being developed that will further advance the breadth and success of genetic medicine.

NF1 Patients Receiving Breast Cancer Screening: Insights from The Ontario High Risk Breast Screening Program.

Neurofibromatosis Type I (NF1) is caused by variants in neurofibromin (). NF1 predisposes to a variety of benign and malignant tumor types, including breast cancer. Women with NF1 <50 years of age possess an up to five-fold increased risk of developing breast cancer compared with the general population.

Tamoxifen therapy in a murine model of myotubular myopathy.

Myotubular myopathy (MTM) is a severe X-linked disease without existing therapies. Here, we show that tamoxifen ameliorates MTM-related histopathological and functional abnormalities in mice, and nearly doubles survival. The beneficial effects of tamoxifen are mediated primarily via estrogen receptor signaling, as demonstrated through in vitro studies and in vivo phenotypic rescue with estradiol.

Dynamin 2 (DNM2) as Cause of, and Modifier for, Human Neuromuscular Disease.

Dynamin 2 (DNM2) belongs to a family of large GTPases that are well known for mediating membrane fission by oligomerizing at the neck of membrane invaginations. Autosomal dominant mutations in the ubiquitously expressed DNM2 cause 2 discrete neuromuscular diseases: autosomal dominant centronuclear myopathy (ADCNM) and dominant intermediate Charcot-Marie-Tooth neuropathy (CMT). CNM and CMT mutations may affect DNM2 in distinct manners: CNM mutations may cause protein hyperactivity with elevated GTPase and fission activities, while CMT mutations could impair DNM2 lipid binding and activity.