Progressive myoclonus epilepsies (PMEs) are a group of rare, inherited disorders manifesting with action myoclonus, tonic-clonic seizures, and ataxia. We exome-sequenced 84 unrelated PME patients of unknown cause and molecularly solved 26 cases (31%). Remarkably, a recurrent de novo mutation c.959G>A (p.Arg320His) in KCNC1 was identified as a novel major cause for PME. Eleven unrelated exome-sequenced (13%) and two patients in a secondary cohort (7%) had this mutation. KCNC1 encodes K V 3.1, a subunit of the K V 3 voltage-gated K + channels, major determinants of high-frequency neuronal firing. Functional analysis of the p.Arg320His mutant channel revealed a dominant-negative loss-of-function effect. Ten patients had pathogenic mutations in known PME-associated genes (NEU1, NHLRC1, AFG3L2, EPM2A, CLN6, SERPINI1). Identification of mutations in PRNP, SACS, and TBC1D24 expand their phenotypic spectrum to PME. These findings provide important insights into the molecular genetic basis of PME and reveal the role of de novo mutations in this disease entity.Correspondence should be addressed to Anna-Elina Lehesjoki (anna-elina.lehesjoki@helsinki.fi). Author Contributions Accession codesMutation nomenclatures correspond to the following canonical Ensembl transcripts: KCNC1, ENST00000265969.6; NEU1, ENST00000375631.4; NHLRC1, ENST00000340650.3; EPM2A, ENST00000367519.3; CLN6, ENST00000249806.5; AFG3L2, ENST00000269143.3; TBC1D24, ENST00000293970.5; SACS, ENST00000382298.3; SERPINI1, ENST00000295777.5; PRNP, ENST00000379440.4; SCN1A, ENST00000303395.4. The raw aligned sequence reads were submitted to the European Genome-phenome Archive (https://www.ebi.ac.uk/ega/home) by Wellcome Trust Sanger Institute under study accession numbers EGAS00001000048 and EGAS00001000386. Competing Financial InterestsAuthors declare no potential competing financial interests. Europe PMC Funders GroupAuthor Manuscript Nat Genet. Author manuscript; available in PMC 2015 July 01. Published in final edited form as:Nat Genet. 5,6 and GOSR2 7 also contribute to cases of PME with preserved cognition. Other PMEs may have additional features, particularly dementia. PME-associated genes encode a variety of proteins, many of them being associated with endosomal and lysosomal function 8,9 , but the associated disease mechanisms are generally poorly understood.The precise clinical diagnosis of specific forms of PME is challenging due to their genetic heterogeneity, phenotypic similarities and overlap of symptoms with other epileptic and neurodegenerative diseases. In many cases, there are no distinguishing clinical features or biomarkers. Consequently, a substantial proportion of PME cases remain without a molecular diagnosis 3 .Here, we aimed to identify the causative genes for unsolved PME cases by employing exome sequencing in unrelated patients assembled from multiple centers in Europe, North America, Asia, and Australia over a 25-year period. The extent of previous molecular studies varied, but all cases were negative for mutations in the ...

The prognosis of advanced melanoma remains poor in spite of treatment advances, emphasizing the importance of additional preventive measures. Flavonoids, natural components of our diet are being investigated for their chemopreventive/therapeutic properties. Microphthalmia-associated transcription factor (Mitf), downstream of Wnt/β-catenin pathway has become an important prognostic marker of melanoma. Here, we show that treatment of 451Lu melanoma cells with the dietary flavonoid fisetin resulted in decreased cell viability with G1-phase arrest and disruption of Wnt/β-catenin signaling. This was accompanied with a decrease in expression of Wnt protein and its co-receptors and a parallel increase in the expression of endogenous Wnt inhibitors. Fisetin-treated cells showed increased cytosolic levels of Axin and β-TrCP and decreased phosphorylation of GSK3-β assocaited with decreased β-catenin stabilization. Fisetin-mediated interference with the functional cooperation between β-catenin and LEF/TCF-2 resulted in downregulation of positively regulated TCF targets such as c-myc, Brn-2 and Mitf. Flowcytometric analysis of Mitf overexpressing cells showed that fisetin repressed Mitf-induced cell proliferation. Finally, administration of fisetin to 451Lu xenografted nude mice resulted in inhibition of tumor development and decreased Mitf expression. Our data suggest that fisetin can be developed as an effective agent against melanoma due to its potential inhibitory effect on β-catenin/Mitf signaling.

By using homozygosity mapping in a consanguineous Pakistani family, we detected linkage of nonsyndromic hearing loss to a 7.6 Mb region on chromosome 3q13.31-q21.1 within the previously reported DFNB42 locus. Subsequent candidate gene sequencing identified a homozygous nonsense mutation (c.1135G>T [p.Glu379X]) in ILDR1 as the cause of hearing impairment. By analyzing additional consanguineous families with homozygosity at this locus, we detected ILDR1 mutations in the affected individuals of 10 more families from Pakistan and Iran. The identified ILDR1 variants include missense, nonsense, frameshift, and splice-site mutations as well as a start codon mutation in the family that originally defined the DFNB42 locus. ILDR1 encodes the evolutionarily conserved immunoglobulin-like domain containing receptor 1, a putative transmembrane receptor of unknown function. In situ hybridization detected expression of Ildr1, the murine ortholog, early in development in the vestibule and in hair cells and supporting cells of the cochlea. Expression in hair cell- and supporting cell-containing neurosensory organs is conserved in the zebrafish, in which the ildr1 ortholog is prominently expressed in the developing ear and neuromasts of the lateral line. These data identify loss-of-function mutations of ILDR1, a gene with a conserved expression pattern pointing to a conserved function in hearing in vertebrates, as underlying nonsyndromic prelingual sensorineural hearing impairment.

This case emphasizes that decisions on predictive testing are very personal and require appropriate counselling.