May 21, 2024 — The National Organization for Rare Disorders (NORD), in partnership with the Tyler James Abizeid Foundation and the MMIHS Foundation, announces the awarding of two separate research grants for Arteriovenous Malformation (AVM) and Megacystis Microcolon Intestinal Hypoperistalsis Syndrome (MMIHS).
These grants, totaling $65,000, were awarded to distinguished researchers at two NORD Rare Disease Centers of Excellence, Duke University School of Medicine’s Duke Health Rare Disease Center and Penn Medicine/Children’s Hospital of Philadelphia.
Arteriovenous Malformation (AVM)
NORD, with funding from the Tyler James Abizeid Foundation, issued one seed grant in the amount of $35,000 for research into Arteriovenous Malformation (AVM) to Dr. Douglas A. Marchuk, PhD; James B. Duke Distinguished Professor at Duke University School of Medicine’s Department of Molecular Genetics and Microbiology.
Dr. Marchuk’s project, titled “Copy Neutral Loss of Heterozygosity as a Driver for Brain Vascular Malformations,” seeks to investigate copy neutral Loss of Heterozygosity (LOH) as a molecular genetic mechanism in the growth of three different vascular malformations: sporadic brain AVMs, Cerebral Cavernous Malformations (CCM), and vascular malformation tissue from Sturge Weber Syndrome. All three of these cases are seeded by the somatic acquisition of a specific point mutation in a growth driver gene that activates the signaling of the encoded protein. However, Marchuk’s team believes that other molecular genetic events in the affected vascular malformation drive additional growth. They hypothesize that copy neutral LOH over the genomic region of the relevant gene could lead to two mutant copies of the mutant allele, leading to a doubling of the activation signal caused by the mutation.
Megacystis Microcolon Intestinal Hypoperistalsis Syndrome (MMIHS)
NORD, with funding from the MMIHS Foundation, issued one seed grant in the amount of $30,000 for research into Megacystis Microcolon Intestinal Hypoperistalsis Syndrome (MMIHS) to Dr. Robert O. Heuckeroth, MD, PhD; Professor of Pediatrics and Developmental Biology at the Children’s Hospital of Philadelphia.
Dr. Heuckeroth’s project is titled, “Phenotypic Class Switching in MMIHS and Visceral Myopathy.” MMIHS is characterized by profound visceral (bowel, bladder, and uterine) smooth muscle weakness. While it seems likely that disease-causing gene mutations directly reduce the “strength” of smooth muscle cells, it is also possible that these mutations change smooth muscle in other ways. For example, while we usually think of smooth muscle as cells that contract and relax, in many disease contexts, smooth muscle can become less contractile and assume a completely different set of cell functions. This process is called “phenotypic class switching.” Dr. Heuckeroth’s team’s goal is to determine if bowel smooth muscle undergo phenotypic class switching in people who have MMIHS or visceral myopathy, since this could have implications for alternative approaches to therapy.
NORD is grateful to the teams behind both of these projects, which will further our collective understanding of rare diseases and potential therapies. NORD also extends gratitude to our funding partners, the Tyler James Abizeid Foundation and the MMIHS Foundation. Learn more about NORD’s Rare Disease Research Grants program.
