We aimed to provide a detailed phenotypic description of status epilepticus (SE) in a large cohort of patients with POLG disease and identify prognostic biomarkers to improve the management of this ...life-threatening condition. In a multinational, retrospective study with data on patients with POLG disease from seven European countries, we identified those who had SE. The age of SE onset, accompanying clinical, laboratory, imaging and genetic findings were analysed. One hundred and ninety-five patients with genetically confirmed POLG disease were recruited, of whom 67% (130/194) had epilepsy. SE was identified in 77% (97/126), with a median age of SE onset of 7 years. SE was the presenting symptom of the disease in 43% (40/93) of those with SE, while 57% (53/93) developed SE during the disease course. Convulsive SE was reported in 97% (91/94) followed by epilepsia partialis continua in 67% (56/84). Liver impairment 78% (74/95), ataxia 69% (60/87), stroke-like episodes 57% (50/88), were the major comorbidities. In the majority (66%; 57/86) with SE this became refractory or super-refractory. The presence of seizures was associated with significantly higher mortality compared to those without (P ≤ 0.001). The median time from SE debut to death was 5 months. SE is a major clinical feature of POLG disease in early and juvenile to adult-onset disease and can be the presenting feature or arise as part of a multisystem disease. It is associated with high morbidity and mortality, with the majority of patients with SE going on to develop refractory or super-refractory SE.
Although the best-known spinocerebellar ataxias (SCAs) are triplet repeat diseases, many SCAs are not caused by repeat expansions. The rarity of individual non-expansion SCAs, however, has made it ...difficult to discern genotype-phenotype correlations. We therefore screened individuals who had been found to bear variants in a non-expansion SCA-associated gene through genetic testing, and after we eliminated genetic groups that had fewer than 30 subjects, there were 756 subjects bearing single-nucleotide variants or deletions in one of seven genes: CACNA1A (239 subjects), PRKCG (175), AFG3L2 (101), ITPR1 (91), STUB1 (77), SPTBN2 (39), or KCNC3 (34). We compared age at onset, disease features, and progression by gene and variant. There were no features that reliably distinguished one of these SCAs from another, and several genes—CACNA1A, ITPR1, SPTBN2, and KCNC3—were associated with both adult-onset and infantile-onset forms of disease, which also differed in presentation. Nevertheless, progression was overall very slow, and STUB1-associated disease was the fastest. Several variants in CACNA1A showed particularly wide ranges in age at onset: one variant produced anything from infantile developmental delay to ataxia onset at 64 years of age within the same family. For CACNA1A, ITPR1, and SPTBN2, the type of variant and charge change on the protein greatly affected the phenotype, defying pathogenicity prediction algorithms. Even with next-generation sequencing, accurate diagnosis requires dialogue between the clinician and the geneticist.
This study describes 756 non-expansion ataxia-affected individuals bearing variants in CACNA1A, PRKCG, AFG3L2, ITPR1, STUB1, SPTBN2, or KCNC3. Ages at onset can range over six decades, in some cases for the very same variant. Moreover, some variants predicted to exert little effect can actually be quite deleterious.
Pathogenic variants in KANSL1 and 17q21.31 microdeletions are causative of Koolen-de Vries syndrome (KdVS), a neurodevelopmental syndrome with characteristic facial dysmorphia. Our previous work has ...shown that syndromic conditions caused by pathogenic variants in epigenetic regulatory genes have identifiable patterns of DNA methylation (DNAm) change: DNAm signatures or episignatures. Given the role of KANSL1 in histone acetylation, we tested whether variants underlying KdVS are associated with a DNAm signature. We profiled whole-blood DNAm for 13 individuals with KANSL1 variants, four individuals with 17q21.31 microdeletions, and 21 typically developing individuals, using Illumina's Infinium EPIC array. In this study, we identified a robust DNAm signature of 456 significant CpG sites in 8 individuals with KdVS, a pattern independently validated in an additional 7 individuals with KdVS. We also demonstrate the diagnostic utility of the signature and classify two KANSL1 VUS as well as four variants in individuals with atypical clinical presentation. Lastly, we investigated tissue-specific DNAm changes in fibroblast cells from individuals with KdVS. Collectively, our findings contribute to the understanding of the epigenetic landscape related to KdVS and aid in the diagnosis and classification of variants in this structurally complex genomic region.
BackgroundNKX2-1-related disorders have a prevalence of 1:500,000 and are therefore considered a rare condition according to the European Commission's definition. The European Reference Network of ...Rare Neurological Disorders is developing the first clinical practice guideline on the management of this condition, with the support of the Andalusian Health Technology Assessment Area, Endo-ERN, ERN-Lung and Imegen, within the framework of the ERNs Guidelines programme (DG SANTE/2018/B3/030). Within the scope of this programme, it becomes necessary to explore the patient perspective in order to include it in the ongoing clinical practice guideline and accompanying patient information booklet.Methods and analysisThis study will use qualitative methods to explore the values, preferences and information needs of patient with NKX2-1-related disorders and their caregivers. Participants will come from a variety of countries throughout Europe. One focus group and four semi-structured interviews will be conducted. Pairs will analyse the data using Grounded Theory. The Andalusian Regional Ministry of Health's Ethics Coordinating Committee for Biomedical Research (Sevilla, Andalucía, Spain) has approved this study protocol (29/03/2022).DiscussionThis is the first study to explore the values, preferences, and information needs of patients with NKX2-1-related disorders. The proposed study's findings will contribute to the generation of useful knowledge that will provide guidance to improve the care given to patients with the studied condition. While this study will provide valuable insights into the perspectives of patients with NKX2-1-related disorders, the findings are unlikely to be generalizable to patients with other conditions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: Variants in SCN8A are associated with a spectrum of epilepsies and neurodevelopmental disorders. Ataxia as a predominant symptom of SCN8A variation has not been well studied. We set out ...to investigate disease mechanisms and genotype–phenotype correlations of SCN8A-related ataxia. Methods: We collected genetic and electro-clinical data of ten individuals from nine unrelated families carrying novel SCN8A variants associated with chronic progressive or episodic ataxia. Electrophysiological characterizations of these variants were performed in ND7/23 cells and cultured neurons. Findings: Variants associated with chronic progressive ataxia either decreased Na+ current densities and shifted activation curves towards more depolarized potentials (p.Asn995Asp, p.Lys1498Glu and p.Trp1266Cys) or resulted in a premature stop codon (p.Trp937Ter). Three variants (p.Arg847Gln and biallelic p.Arg191Trp/p.Asp1525Tyr) were associated with episodic ataxia causing loss-of-function by decreasing Na+ current densities or a hyperpolarizing shift of the inactivation curve. Two additional episodic ataxia-associated variants caused mixed gain- and loss-of function effects in ND7/23 cells and were further examined in primary murine hippocampal neuronal cultures. Neuronal firing in excitatory neurons was increased by p.Arg1629His, but decreased by p.Glu1201Lys. Neuronal firing in inhibitory neurons was decreased for both variants. No functional effect was observed for p.Arg1913Trp. In four individuals, treatment with sodium channel blockers exacerbated symptoms. Interpretation: We identified episodic or chronic ataxia as predominant phenotypes caused by variants in SCN8A. Genotype-phenotype correlations revealed a more pronounced loss-of-function effect for variants causing chronic ataxia. Sodium channel blockers should be avoided under these conditions. Funding: BMBF, DFG, the Italian Ministry of Health, University of Tuebingen.
Variants in SCN8A are associated with a spectrum of epilepsies and neurodevelopmental disorders. Ataxia as a predominant symptom of SCN8A variation has not been well studied. We set out to ...investigate disease mechanisms and genotype-phenotype correlations of SCN8A-related ataxia.
We collected genetic and electro-clinical data of ten individuals from nine unrelated families carrying novel SCN8A variants associated with chronic progressive or episodic ataxia. Electrophysiological characterizations of these variants were performed in ND7/23 cells and cultured neurons.
Variants associated with chronic progressive ataxia either decreased Na
current densities and shifted activation curves towards more depolarized potentials (p.Asn995Asp, p.Lys1498Glu and p.Trp1266Cys) or resulted in a premature stop codon (p.Trp937Ter). Three variants (p.Arg847Gln and biallelic p.Arg191Trp/p.Asp1525Tyr) were associated with episodic ataxia causing loss-of-function by decreasing Na
current densities or a hyperpolarizing shift of the inactivation curve. Two additional episodic ataxia-associated variants caused mixed gain- and loss-of function effects in ND7/23 cells and were further examined in primary murine hippocampal neuronal cultures. Neuronal firing in excitatory neurons was increased by p.Arg1629His, but decreased by p.Glu1201Lys. Neuronal firing in inhibitory neurons was decreased for both variants. No functional effect was observed for p.Arg1913Trp. In four individuals, treatment with sodium channel blockers exacerbated symptoms.
We identified episodic or chronic ataxia as predominant phenotypes caused by variants in SCN8A. Genotype-phenotype correlations revealed a more pronounced loss-of-function effect for variants causing chronic ataxia. Sodium channel blockers should be avoided under these conditions.
BMBF, DFG, the Italian Ministry of Health, University of Tuebingen.
