1. ABCC9-related Intellectual disability Myopathy Syndrome is a KATP channelopathy with loss-of-function mutations in ABCC9
- Author
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Smeland, Marie F, McClenaghan, Conor, Roessler, Helen I, Savelberg, Sanne, Hansen, Geir Åsmund Myge, Hjellnes, Helene, Arntzen, Kjell Arne, Müller, Kai Ivar, Dybesland, Andreas Rosenberger, Harter, Theresa, Sala-Rabanal, Monica, Emfinger, Chris H, Huang, Yan, Singareddy, Soma S, Gunn, Jamie, Wozniak, David F, Kovacs, Attila, Massink, Maarten, Tessadori, Federico, Kamel, Sarah M, Bakkers, Jeroen, Remedi, Maria S, Van Ghelue, Marijke, Nichols, Colin G, van Haaften, Gijs, Smeland, Marie F, McClenaghan, Conor, Roessler, Helen I, Savelberg, Sanne, Hansen, Geir Åsmund Myge, Hjellnes, Helene, Arntzen, Kjell Arne, Müller, Kai Ivar, Dybesland, Andreas Rosenberger, Harter, Theresa, Sala-Rabanal, Monica, Emfinger, Chris H, Huang, Yan, Singareddy, Soma S, Gunn, Jamie, Wozniak, David F, Kovacs, Attila, Massink, Maarten, Tessadori, Federico, Kamel, Sarah M, Bakkers, Jeroen, Remedi, Maria S, Van Ghelue, Marijke, Nichols, Colin G, and van Haaften, Gijs
- Abstract
Mutations in genes encoding KATP channel subunits have been reported for pancreatic disorders and Cantú syndrome. Here, we report a syndrome in six patients from two families with a consistent phenotype of mild intellectual disability, similar facies, myopathy, and cerebral white matter hyperintensities, with cardiac systolic dysfunction present in the two oldest patients. Patients are homozygous for a splice-site mutation in ABCC9 (c.1320 + 1 G > A), which encodes the sulfonylurea receptor 2 (SUR2) subunit of KATP channels. This mutation results in an in-frame deletion of exon 8, which results in non-functional KATP channels in recombinant assays. SUR2 loss-of-function causes fatigability and cardiac dysfunction in mice, and reduced activity, cardiac dysfunction and ventricular enlargement in zebrafish. We term this channelopathy resulting from loss-of-function of SUR2-containing KATP channels ABCC9-related Intellectual disability Myopathy Syndrome (AIMS). The phenotype differs from Cantú syndrome, which is caused by gain-of-function ABCC9 mutations, reflecting the opposing consequences of KATP loss- versus gain-of-function.
- Published
- 2019