Neurodevelopmental and Epilepsy Phenotypes in Individuals With Missense Variants in the Voltage-Sensing and Pore Domains of KCNH5

Background and Objectives KCNH5 encodes the voltage-gated potassium channel EAG2/Kv10.2. We aimed to delineate the neurodevelopmental and epilepsy phenotypic spectrum associated with de novo KCNH5 variants.Methods We screened 893 individuals with developmental and epileptic encephalopathies for KCNH5 variants using targeted or exome sequencing. Additional individuals with KCNH5 variants were identified through an international collaboration. Clinical history, EEG, and imaging data were analyzed; seizure types and epilepsy syndromes were classified. We included 3 previously published individuals including additional phenotypic details.Results We report a cohort of 17 patients, including 9 with a recurrent de novo missense variant p.Arg327His, 4 with a recurrent missense variant p.Arg333His, and 4 additional novel missense variants. All variants were located in or near the functionally critical voltage-sensing or pore domains, absent in the general population, and classified as pathogenic or likely pathogenic using the American College of Medical Genetics and Genomics criteria. All individuals presented with epilepsy with a median seizure onset at 6 months. They had a wide range of seizure types, including focal and generalized seizures. Cognitive outcomes ranged from normal intellect to profound impairment. Individuals with the recurrent p.Arg333His variant had a self-limited drug-responsive focal or generalized epilepsy and normal intellect, whereas the recurrent p.Arg327His variant was associated with infantile-onset DEE. Two individuals with variants in the pore domain were more severely affected, with a neonatal-onset movement disorder, early-infantile DEE, profound disability, and childhood death.Discussion We describe a cohort of 17 individuals with pathogenic or likely pathogenic missense variants in the voltage-sensing and pore domains of Kv10.2, including 14 previously unreported individuals. We present evidence for a putative emerging genotype-phenotype correlation with a spectrum of epilepsy and cognitive outcomes. Overall, we expand the role of EAG proteins in human disease and establish KCNH5 as implicated in a spectrum of neurodevelopmental disorders and epilepsy.</p

Genetic landscape of congenital insensitivity to pain and hereditary sensory and autonomic neuropathies

Congenital insensitivity to pain (CIP) and hereditary sensory and autonomic neuropathies (HSAN) are clinically and genetically heterogeneous disorders exclusively or predominantly affecting the sensory and autonomic neurons. Due to the rarity of the diseases and findings based mainly on single case reports or small case series, knowledge about these disorders is limited. Here, we describe the molecular workup of a large international cohort of CIP/HSAN patients including patients from normally under-represented countries. We identify 80 previously unreported pathogenic or likely pathogenic variants in a total of 73 families in the >20 known CIP/HSAN-associated genes. The data expand the spectrum of disease-relevant alterations in CIP/HSAN, including novel variants in previously rarely recognized entities such as ATL3-, FLVCR1- and NGF-associated neuropathies and previously under-recognized mutation types such as larger deletions. In silico predictions, heterologous expression studies, segregation analyses and metabolic tests helped to overcome limitations of current variant classification schemes that often fail to categorize a variant as disease-related or benign. The study sheds light on the genetic causes and disease-relevant changes within individual genes in CIP/HSAN. This is becoming increasingly important with emerging clinical trials investigating subtype or gene-specific treatment strategies

Analysis of the LMNA gene and the SH3TC2 gene among Czech patients with hereditary neuropathy Charcot-Marie-Tooth type 1 and 2

My PhD thesis can be devided into two parts: 1. Hereditary motor-sensory neuropathies (HMSN) 2. Selected muscle disorders The main emphasis was on the first part - hereditary motor and sensory neuropathies. Research was focused on autosomal recessive forms - demyelinating type CMT4C and axonal type CMT2B1. Most of the results obtained are related to these disorders. Data, which were obtained, are unique and were published in international journals with impact factor. Results obtained from CMT4C study are accepted for publication in Clinical Genetics. Results obtained in LMNA study (CMT2B1) were published in Journal of Human Genetics. The author performed and validated these new methods and original results, which are due to be used in genetic molecular testing of patients with hereditary neuropathies and muscle disorders: 1. Sequencing of all coding exons of the SH3TC2 gene. First mutations in the SH3TC2 gene in Czech HMSN I patients were found. 2. The prevalent mutation among Czech CMT4C patients was proven to be p.Arg954Stop. 3. Real-time PCR assay targeted at detection of the prevalent mutation p.Arg954Stop in the SH3TC2 gene was validated and is now used in our lab on a daily basis as a quick and efficient screening. 4. Molecular genetic testing of the SH3TC2 gene was introduced into the routine..

Analysis of the LMNA gene and the SH3TC2 gene among Czech patients with hereditary neuropathy Charcot-Marie-Tooth type 1 and 2

My PhD thesis can be devided into two parts: 1. Hereditary motor-sensory neuropathies (HMSN) 2. Selected muscle disorders The main emphasis was on the first part - hereditary motor and sensory neuropathies. Research was focused on autosomal recessive forms - demyelinating type CMT4C and axonal type CMT2B1. Most of the results obtained are related to these disorders. Data, which were obtained, are unique and were published in international journals with impact factor. Results obtained from CMT4C study are accepted for publication in Clinical Genetics. Results obtained in LMNA study (CMT2B1) were published in Journal of Human Genetics. The author performed and validated these new methods and original results, which are due to be used in genetic molecular testing of patients with hereditary neuropathies and muscle disorders: 1. Sequencing of all coding exons of the SH3TC2 gene. First mutations in the SH3TC2 gene in Czech HMSN I patients were found. 2. The prevalent mutation among Czech CMT4C patients was proven to be p.Arg954Stop. 3. Real-time PCR assay targeted at detection of the prevalent mutation p.Arg954Stop in the SH3TC2 gene was validated and is now used in our lab on a daily basis as a quick and efficient screening. 4. Molecular genetic testing of the SH3TC2 gene was introduced into the routine..

Additional file 1: of Detection rate of causal variants in severe childhood epilepsy is highest in patients with seizure onset within the first four weeks of life

Part I Age distribution among patients, first box plot is age of seizure onset, second age of inclusion into study. Part II List off all genes included in panel. Part III Process of CNV analysis. Part IV List of variants of uncertain significance or likely benign found in our cohort. Part V. Part VI Advantages of the gene panel testing. (DOCX 150 kb