Discovery of MEDNIK syndrome



Researchers at the University of Pittsburgh School of Medicine have successfully induced human insulin-producing cells, known as beta cells, to replicate robustly in a living animal, as well as in the lab. The discovery not only could improve models and methods for studying diabetes, but also opens up new possibilities for treating the condition. “Most

Full Post: Important discovery in human insulin-producing cells

Canadian researchers announce the discovery of MEDNIK Syndrome, a debilitating genetic syndrome.

In a study published today in the online version of PLoS Genetics, and in the December edition, a research team led by Dr. Patrick Cossette, from the Université de Montréal Hospital Research Centre (CRCHUM) and Associate Professor, Université de Montréal (U de M), has demonstrated that this syndrome is caused by a newly found mutation in the AP1S1 gene.

MEDNIK syndrome was discovered in a group of families in Quebec from the Kamouraska region, sharing a common ancestor, suspected from clinical manifestations showing striking similarities to those of a similar syndrome. Caused by a mutation in the AP1S1 gene, this syndrome is characterized by mental retardation, enteropathy, deafness, and peripheral neuropathy, ichthyosis, and keratodermia (MEDNIK). ”Our observations strongly suggest that MEDNIK Syndrome is caused by impaired development of various neural networks, including the spinal chord (ataxia and neuropathy), the inner ear (sensorineural deafness) and possibly the brain (microcephaly and psychomotor retardation),” notes Dr. Cossette. ”Disruption of the AP1S1 gene in humans may be associated with more widespread perturbation in the development of various organs, including the gut and the skin. These results suggest interesting avenues for both basic and clinical research to improve our understanding of the mechanisms underlying MEDNIK and related genetic neurocutaneous syndromes.”

By using zebrafish as an animal model, the team of researchers from CRCHUM, U de M, Ontario Institute for Cancer Research, McGill University, Université de Sherbrooke, and Centre hospitalier régional du Grand-Portage in Rivière-du-Loup observed that the loss of the AP1S1 gene resulted in these broad defects, including severe motor deficits due to impairment of spinal cord development. By inducing the expression of the human AP1S1 gene instead of the zebrafish gene, the research team found that the normal human type could rescue these developmental deficits but not the AP1S1 gene bearing the disease-related mutation. This research appears to be the first report of a mutation in human AP1S1.

http://www.chumtl.qc.ca/

Link




Severe combined immunodeficiency (SCID) is an inherited disease sometimes known as ‘Boy in the bubble syndrome’, because the patient lacks one or more type of immune cell, making them very susceptible to infections. Dik van Gent and colleagues, at Erasmus Medical Center, The Netherlands, have now identified a new genetic cause of SCID characterized by

Full Post: Discovery of new genetic cause severe combined immunodeficiency (SCID)



A team of scientists has discovered a new syndrome associated with severe congenital neutropenia (SCN), a rare disorder in which children lack sufficient infection-fighting white cells, and identified the genetic cause of the syndrome: mutations in the gene Glucose-6-phosphatase, catalytic subunit 3 (G6PC3). The findings, which are published in the Jan. 1, 2009 issue of

Full Post: Discovery of new syndrome associated with severe congenital neutropenia



Writing in this week’s Journal of the American Medical Association , UC Davis M.I.N.D. Institute researchers urge physicians to test for mutations of the fragile X gene in patients of all ages. That’s because, after decades of research, it is clear that mutations in this gene cause a range of diseases, including neurodevelopmental delays and

Full Post: Researchers urge physicians to test for fragile X gene mutations in patients of all ages



A multidisciplinary research team at Case Western Reserve University led by Gary Landreth, Ph.D., a professor in the School of Medicine’s Department of Neurosciences, has uncovered a common genetic pathway for a number of birth defects that affect the development of the heart and head. Abnormal development of the jaw, palate, brain and heart are

Full Post: Researchers discover genetic basis for some common congenital birth defects



A University of British Columbia geneticist has discovered a gene mutation that can cause the most common eye cancer - uveal melanoma. Catherine Van Raamsdonk, an assistant professor of medical genetics in the UBC Faculty of Medicine and a team of researchers, have discovered a genetic mutation in a gene called GNAQ that could be

Full Post: Cause of uveal melanoma discovered, most common eye cancer