Referenced in: none

Automatically associated channels: Kir1.1 , Kir6.2

Title: Switching to sulphonylureas in children with iDEND syndrome caused by KCNJ11 mutations results in improved cerebellar perfusion.

Authors: Wojciech Fendler, Iwona Pietrzak, Melissa F Brereton, Carolina Lahmann, Mariusz Gadzicki, Malgorzata Bienkiewicz, Izabela Drozdz, Maciej Borowiec, Maciej T Malecki, Frances M Ashcroft, Wojciech M Mlynarski

Journal, date & volume: Diabetes Care, 2013 Aug , 36, 2311-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23462667

Abstract
Activating mutations in the KCNJ11 gene, encoding the Kir6.2 subunit of the KATP channel, result in permanent neonatal diabetes mellitus. They also may cause neurologic symptoms such as mental retardation and motor problems (iDEND syndrome) and epilepsy (DEND syndrome). Sulphonylurea (SU) treatment is reported to alleviate both the neurologic symptoms and diabetes in such cases. The study aimed to establish the magnitude and functional basis of the effect of SUs on the neurologic phenotype in children with iDEND using neuroimaging before and after insulin replacement with glibenclamide.To localize and quantify the effect of glibenclamide administration, we performed single-photon emission computed tomography in seven patients with different mutations in KCNJ11. In five patients, measurements before and after initiation of SU treatment were performed. RESULTS Significant changes in single-photon emission computed tomography signal intensity after transfer to SU therapy were restricted to the cerebellum, consistent with previous data showing high Kir6.2 expression in this brain region. Cerebellar perfusion improved for both left (P = 0.006) and right (P = 0.01) hemispheres, with the mean improvement being 26.7 ± 7.1% (n = 5). No patients showed deterioration of cerebellar perfusion on SU therapy. Electrophysiological studies revealed a good correlation between the magnitude of KATP channel dysfunction and the clinical phenotype; mutant channels with the greatest reduction in adenosine 5'-triphosphate inhibition were associated with the most severe neurologic symptoms.We conclude it is likely that at least some of the beneficial effects of SU treatment on neurodevelopment in iDEND patients result from improved cerebellar perfusion.