title: Targeted next generation sequencing of a panel of autism-related genes identifies an EHMT1 mutation in a Kleefstra syndrome patient with autism and normal intellectual performance.
abstract: Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with unknown genetic and environmental causation in most of the affected individuals. On the other hand, there are a growing number of ASD-associated syndromes, where the exact genetic origin can be revealed. Here we report a method, which included the targeted next generation sequencing (NGS) and filtering of 101 ASD associated genes, followed by database search. Next, RNA sequencing was used to study the region of interest at the transcriptional level. Using this workflow, we identified a de novo mutation in the euchromatic histone-lysine N-methyltransferase 1 gene (EHMT1) of an autistic patient with dysmorphisms. Sequencing of EHMT1 transcripts showed that the premature termination codon (Trp1138Ter) created by a single nucleotide change elicited nonsense-mediated mRNA decay, which led to haploinsufficiency already at the transcriptional level. Database and literature search provided evidence that this mutation caused Kleefstra syndrome (KS), which was confirmed by the presence of the disorder-specific phenotype in the patient. We provide a proof of principle that the implemented method is capable to elucidate the genetic etiology of individuals with syndromic autism. The novel mutation detected in the EHMT1 gene is responsible for KS's symptoms. In addition, further genetic factors might be involved in the ASD pathogenesis of the patient including a missense DPP6 mutation (Arg322Cys), which segregated with the autistic phenotype within the family.
authors.affiliation: BioTalentum Ltd., Gödöllő, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Bock
authors.affiliation: Autism Foundation, Budapest, Hungary.
authors.forename: Krisztina
authors.initials: K
authors.lastname: Németh
authors.affiliation: Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary.
authors.forename: Klára
authors.initials: K
authors.lastname: Pentelényi
authors.affiliation: Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Balicza
authors.affiliation: Autism Foundation, Budapest, Hungary.
authors.forename: Anna
authors.initials: A
authors.lastname: Balázs
authors.affiliation: Institute of Genomic Medicine and Rare Disorders, Semmelweis University, Budapest, Hungary.
authors.forename: Mária Judit
authors.initials: MJ
authors.lastname: Molnár
authors.affiliation: Laboratory of Neurodevelopmental Biology, Gedeon Richter Plc., Budapest, Hungary.
authors.forename: Viktor
authors.initials: V
authors.lastname: Román
authors.affiliation: Laboratory of Molecular Cell Biology, Gedeon Richter Plc., Budapest, Hungary.
authors.forename: József
authors.initials: J
authors.lastname: Nagy
authors.affiliation: Laboratory of Cognitive Pharmacology, Gedeon Richter Plc., Budapest, Hungary.
authors.forename: György
authors.initials: G
authors.lastname: Lévay
authors.affiliation: BioTalentum Ltd., Gödöllő, Hungary.
authors.forename: Julianna
authors.initials: J
authors.lastname: Kobolák
authors.affiliation: BioTalentum Ltd., Gödöllő, Hungary. Electronic address: andras.dinnyes@biotalentum.hu.
authors.forename: András
authors.initials: A
authors.lastname: Dinnyés
mesh_terms: D001321:Autistic Disorder / Q000209:etiology / Q000235:genetics; D002648:Child; D002872:Chromosome Deletion; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D019465:Craniofacial Abnormalities / Q000209:etiology / Q000235:genetics*; D005260:Female; D057895:Haploinsufficiency; D006330:Heart Defects, Congenital / Q000209:etiology / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics*; D006801:Humans; D008607:Intellectual Disability / Q000209:etiology / Q000235:genetics*; D009154:Mutation; D059365:Nonsense Mediated mRNA Decay; D010375:Pedigree
chemical_list: C455847:EHMT1 protein, human; D011495:Histone-Lysine N-Methyltransferase
keywords: Autism spectrum disorder; DPP6; EHMT1; NGS; NMD; Targeted; Variant