Expanding the genotype-phenotype spectrum in SCN8A-related disorders.

BACKGROUND: SCN8A-related disorders are a group of variable conditions caused by pathogenic variations in SCN8A. Online Mendelian Inheritance in Man (OMIM) terms them as developmental and epileptic encephalopathy 13, benign familial infantile seizures 5 or cognitive impairment with or without cerebellar ataxia. METHODS: In this study, we describe clinical and genetic results on eight individuals from six families with SCN8A pathogenic variants identified via exome sequencing. RESULTS: Clinical findings ranged from normal development with well-controlled epilepsy to significant developmental delay with treatment-resistant epilepsy. Three novel and three reported variants were observed in SCN8A. Electrophysiological analysis in transfected cells revealed a loss-of-function variant in Patient 4. CONCLUSIONS: This work expands the clinical and genotypic spectrum of SCN8A-related disorders and provides electrophysiological results on a novel loss-of-function SCN8A variant.

Trajectories of parent well-being in children with drug-resistant epilepsy.

OBJECTIVE: This longitudinal cohort study aimed to identify trajectories of parent well-being over the first 2 years after their child's evaluation for candidacy for epilepsy surgery, and to identify the baseline clinical and demographic characteristics associated with these trajectories. Parent well-being was based on parent depressive and anxiety symptoms and family resources (i.e., family mastery and social support). METHODS: Parents of 259 children with drug-resistant epilepsy (105 of whom eventually had surgery) were recruited from eight epilepsy centers across Canada at the time of their evaluation for epilepsy surgery candidacy. Participants were assessed at baseline and 6-month, 1-year, and 2-year follow-up. The trajectories of parents' depressive symptoms, anxiety symptoms, and family resources were jointly estimated using multigroup latent class growth models. RESULTS: The analyses identified three trajectories: an optimal-stable group with no/minimal depressive or anxiety symptoms, and high family resources that remained stable over time; a mild-decreasing-plateau group with mild depressive and anxiety symptoms that decreased over time then plateaued, and intermediate family resources that remained stable; and a moderate-decreasing group with moderate depressive and anxiety symptoms that decreased slightly, and low family resources that remained stable over time. Parents of children with higher health-related quality of life, fathers, and parents who had higher household income were more likely to have better trajectories of well-being. Treatment type was not associated with the trajectory groups, but parents whose children were seizure-free at the time of the last follow-up were more likely to have better trajectories (optimal-stable or mild-decreasing-plateau trajectories). SIGNIFICANCE: This study documented distinct trajectories of parent well-being, from the time of the child's evaluation for epilepsy surgery. Parents who present with anxiety and depressive symptoms and low family resources do not do well over time. They should be identified and offered supportive services early in their child's epilepsy treatment history.

Pre-Operative Predictors of Health-Related Quality of Life Two Years After Pediatric Epilepsy Surgery: A Prospective Cohort Study.

PURPOSE: Seizure freedom is an important predictor of health-related quality of life (HRQOL) after pediatric epilepsy surgery. This study aimed to identify the pre-operative predictors of HRQOL 2 years after epilepsy surgery in children with drug-resistant epilepsy. METHODS: This multicenter prospective cohort study assessed pre-operative predictors including child (demographics and clinical variables), caregiver (including caregiver depressive and anxiety symptoms) and family characteristics. HRQOL was assessed using the Quality of Life in Childhood Epilepsy Questionnaire (QOLCE)-55 pre-operatively and 2-years after surgery. Univariable linear regression analyses were done to identify significant preoperative predictors of HRQOL 2-years after surgery, followed by multivariable regression. RESULTS: Ninety-five children underwent surgery, mean age was 11.4 (SD=4.2) years, and 59 (62%) were male. Mean QOLCE scores were 57.4 (95%CI: 53.8, 61.0) pre-operatively and 65.6 (95%CI: 62.0, 69.1) after surgery. Univariable regression showed fewer anti-seizure medications (ß=-6.1 [95%CI: -11.2, -1.0], p = 0.019), older age at seizure onset (ß=1.6 [95%CI: 0.8, 2.4], p<0.001), higher pre-operative HRQOL (ß=0.7 [95%CI: 0.5, 0.8], p<0.001), higher family resources (ß=0.6 [95%CI: 0.3, 0.9], p<0.001), better family relationships (ß=1.7 [95%CI: 0.3, 3.1], p = 0.017) and lower family demands (ß=-0.9 [95%CI: -1.5, -0.4], p<0.001) were associated with higher HRQOL after surgery. Caregiver characteristics did not predict HRQOL after surgery (p>0.05). Multivariable regression showed older age at seizure onset (ß=4.6 [95%CI: 1.6, 7.6], p = 0.003) and higher pre-operative HRQOL (ß=10.2 [95%CI: 6.8, 13.6], p<0.001) were associated with higher HRQOL after surgery. CONCLUSION: This study underscores the importance of optimizing pre-operative HRQOL to maximize HRQOL outcome after pediatric epilepsy surgery.

Expanding the genotype-phenotype spectrum in SCN8A-related disorders.

Background: SCN8A-related disorders are a group of variable conditions caused by pathogenic variations in SCN8A. Online Mendelian Inheritance in Man (OMIM) terms them as developmental and epileptic encephalopathy 13, benign familial infantile seizures 5 or cognitive impairment with or without cerebellar ataxia. Methods: In this study, we describe clinical and genetic results on eight individuals from six families with SCN8A pathogenic variants identified via exome sequencing. Results: Clinical findings ranged from normal development with well-controlled epilepsy to significant developmental delay with treatment-resistant epilepsy. Three novel and three reported variants were observed in SCN8A. Electrophysiological analysis in transfected cells revealed a loss-of-function variant in Patient 4. Conclusions: This work expands the clinical and genotypic spectrum of SCN8A-related disorders and provides electrophysiological results on a novel loss-of-function SCN8A variant.

A longitudinal cohort study of mediators of health-related quality of life after pediatric epilepsy surgery or medical treatment.

OBJECTIVES: The purpose of this longitudinal cohort study was to examine the variables that influence health-related quality of life (HRQOL) after epilepsy surgery in children. We examined whether treatment type (surgical vs medical therapy) and seizure control are related to other variables that have been shown to influence HRQOL, namely depressive symptoms in children with epilepsy or their parents, and the availability of family resources. METHODS: In total, 265 children with drug-resistant epilepsy were recruited from eight epilepsy centers across Canada at the time of their evaluation for candidacy for epilepsy surgery and were assessed at baseline, 6-month, 1-year, and 2-year follow-up. Parents completed the Quality of Life in Childhood Epilepsy Questionnaire (QOLCE-55) and measures of family resources and depression; children completed depression inventories. Causal mediation analyses using natural effect models were used to evaluate the extent to which the relationship between treatment and HRQOL was explained by seizure control, child and parent depressive symptoms, and family resources. RESULTS: Overall, 111 children underwent surgery and 154 were treated with medical therapy only. The HRQOL scores of surgical patients were 3.4 points higher (95% confidence interval [CI]: -0.2, 7.0) relative to medical patients at the 2-year follow-up after adjusting for baseline covariates, with 66% of the effect of surgery attributed to seizure control. Child or parent depressive symptoms and family resources had negligible mediation effects between treatment and HRQOL. The effect of seizure control on HRQOL was not mediated by child or parent depressive symptoms, or by family resources. SIGNIFICANCE: The findings demonstrate that seizure control is on the causal pathway between epilepsy surgery and improved HRQOL in children with drug-resistant epilepsy. However, child and parent depressive symptoms and family resources were not significant mediators. The results highlight the importance of achieving seizure control to improve HRQOL.

Trajectory of Health-Related Quality of Life After Pediatric Epilepsy Surgery.

Importance: Health-related quality of life (HRQOL) is regarded as a key outcome for evaluating treatment efficacy. However, it is uncertain how HRQOL evolves after epilepsy surgery compared with medical therapy, such as whether it continues to improve over time, improves and then remains stable, or deteriorates after a period of time. Objective: To assess trajectory of HRQOL over 2 years in children with drug-resistant epilepsy (DRE) treated with surgery compared with medical therapy. Design, Setting, and Participants: Prospective cohort study assessing HRQOL longitudinally over 2 years. Participants were children recruited from 8 epilepsy centers in Canada from 2014 to 2019 with suspected DRE aged 4 to 18 years who were evaluated for surgery. Data were analyzed from May 2014 to December 2021. Exposures: Epilepsy surgery or medical therapy. Main Outcomes and Measures: HRQOL was measured using the Quality of Life in Childhood Epilepsy Questionnaire (QOLCE)-55. HRQOL and seizure frequency were assessed at baseline, 6-month, 1-year, and 2-year follow-ups. Clinical, parent, and family characteristics were assessed at baseline. A linear mixed model was used to evaluate HRQOL over time, adjusting for baseline clinical, parent, and family characteristics. Results: There were 111 surgical and 154 medical patients (mean [SD] age at baseline was 11.0 [4.1] years; 118 [45%] were female). At baseline, HRQOL was similar among surgical and medical patients. HRQOL of surgical patients was 3.0 (95% CI, -0.7 to 6.8) points higher at 6-month, 4.9 (95% CI, 0.7 to 9.1) points higher at 1-year, and 5.1 (95% CI, 0.7 to 9.5) points higher at 2-year follow-ups compared with medical patients. Surgical patients experienced greater improvements in social functioning relative to medical patients, but not for cognitive, emotional, and physical functioning. At 2-year follow-up, 72% of surgical patients were seizure-free, compared with 33% of medical patients. Seizure-free patients reported higher HRQOL than those who were not. Conclusions and Relevance: This study provided evidence on the association between epilepsy surgery and children's HRQOL, with improvement in HRQOL occurring within the first year and remaining stable 2 years after surgery. By demonstrating that surgery improved seizure freedom and HRQOL, which has downstream effects such as better educational attainment, reduced health care resource utilization, and health care cost, these findings suggest that the high costs of surgery are justified, and that improved access to epilepsy surgery is necessary.

Targeted Whole Exome Sequencing in Children With Early-Onset Epilepsy: Parent Experiences.

This study investigated the experiences of 25 caregivers of children with early-onset, treatment-resistant epilepsy who pursued whole exome sequencing to determine the impact of the test results on their child's treatment. Caregivers who consented to be recontacted were recruited from a previous study investigating the diagnostic yield of whole exome sequencing. A semistructured interview addressed questions based on one of 2 study phases. The first phase discussed the decision-making process for genetic testing (15 interviews), which revealed 4 major themes: (1) prognosis, (2) engagement, (3) concerns, and (4) autonomy. The second phase discussed the impact of genetic testing on treatment (10 interviews), which revealed 3 major themes: (1) testing features, (2) emotional impact, and (3) treatment outcomes. Overall, parents pursued genetic testing to obtain a clear prognosis, inform treatment decisions, engage with other families, and exercise autonomy. Caregivers felt that early testing is warranted to inform their child's diagnostic odyssey.

Clinician preferences for neurotechnologies in pediatric drug-resistant epilepsy: A discrete choice experiment.

OBJECTIVE: Novel and minimally invasive neurotechnologies offer the potential to reduce the burden of epilepsy while avoiding the risks of conventional resective surgery. Few neurotechnologies have been tested in randomized controlled trials with pediatric populations, leaving clinicians to face decisions about whether to recommend these treatments with insufficient evidence about the relevant risks and benefits. This study specifically explores the preferences of clinicians for treating pediatric drug-resistant epilepsy (DRE) with novel neurotechnologies. METHODS: A discrete-choice experiment (DCE) was designed to elicit the preferences of clinicians with experience in treating children with DRE using novel neurotechnological interventions. The preferences for six key attributes used when making treatment decisions (chances of clinically significant improvement in seizures, major and minor risks from intervention, availability of evidence, financial burden for the family, and access to the intervention) were estimated using a conditional logit model. The estimates from this model were then used to predict the adoption of existing novel neurotechnological interventions. RESULTS: Sixty-eight clinicians completed the survey: 33 neurosurgeons, 28 neurologists, and 7 other clinicians. Most clinicians were working in the United States (74%), and the remainder (26%) in Canada. All attributes, apart from the nearest location with access to the intervention, influenced preferences significantly. The chance of clinically significant improvement in seizures was the most positive influence on clinician preferences, but low-quality evidence and a higher risk of major complications could offset these preferences. Of the existing neurotechnological interventions, vagus nerve stimulation was predicted to have the highest likelihood of adoption; deep brain stimulation had the lowest likelihood of adoption. SIGNIFICANCE: The preferences of clinicians are drive primarily by the likelihood of achieving seizure freedom for their patients, but preferences for an intervention are largely eradicated if only low quality of evidence supporting the intervention is available. Until better evidence supporting the use of potentially effective, novel neurotechnologies becomes available, clinicians are likely to prefer more established treatments.

Understanding Attributes that Influence Physician and Caregiver Decisions About Neurotechnology for Pediatric Drug-Resistant Epilepsy: A Formative Qualitative Study to Support the Development of a Discrete Choice Experiment.

OBJECTIVE: This study reports formative qualitative research used to analyze decision making regarding neurotechnological interventions for pediatric drug-resistant epilepsy from the perspective of physicians and caregivers and the derivation of attributes for a discrete choice experiment. METHODS: Purposive and convenience sampling was used to recruit physicians and caregivers. Physician focus group sessions were held at key national conferences in the USA and Canada. Caregivers were approached through clinics with established epilepsy surgery programs in the USA and Canada. Thematic analysis was used to identify critical features of decisions about treatment outcomes, procedural trade-offs, values, and concerns surrounding conventional and novel pediatric drug-resistant epilepsy interventions among physicians and caregivers. RESULTS: The results highlight the presence of central attributes that are considered by both groups in decision making, such as "chances of seizure freedom", "risk", "availability of evidence", and "cost to families", as well as attributes that reflect important differences between groups. Physicians were focused on the specifics of treatment options, while caregivers thought more holistically, considering the overall well-being of their children. DISCUSSION: The findings shaped the development of a discrete choice experiment to understand the likely uptake of different neurotechnologies. We identified differences in decision making and thus designed two discrete choice experiments to elicit preferences for pediatric drug-resistant epilepsy treatments, one aimed at clinicians and one at caregivers. The variation we observed highlights the value of seeking to understand the influences at the point of clinical decision making and incorporating this information into care.

Choice and Trade-offs: Parent Decision Making for Neurotechnologies for Pediatric Drug-Resistant Epilepsy.

This qualitative study investigated factors that guide caregiver decision making and ethical trade-offs for advanced neurotechnologies used to treat children with drug-resistant epilepsy. Caregivers with affected children were recruited to semi-structured focus groups or interviews at one of 4 major epilepsy centers in Eastern and Western Canada and the USA (n = 22). Discussions were transcribed and qualitative analytic methods applied to examine values and priorities (eg, risks, benefits, adherence, invasiveness, reversibility) of caregivers pertaining to novel technologies to treat drug-resistant epilepsy. Discussions revealed 3 major thematic branches for decision making: (1) features of the intervention-risks and benefits, with an emphasis on an aversion to perceived invasiveness; (2) decision drivers-trust in the clinical team, treatment costs; and (3) quality of available information about neurotechnological options. Overall, caregivers' definition of treatment success is more expansive than seizure freedom. The full involvement of their values and priorities must be considered in the decision-making process.

Seizure action plans in the pediatric population with epilepsy: Uptake, determinants, and parental interest in a mobile application.

BACKGROUND: Status epilepticus (SE) is a common pediatric neurological emergency that requires timely treatment to minimize morbidity and mortality, yet administration of rescue medications is often delayed and underdosed. Seizure action plans (SAPs) outline the steps that should be taken by parents and caregivers in case of SE in order to optimize patient outcomes. Our study determined the uptake of SAPs in a pediatric population with epilepsy and assessed parental interest in a SAP mobile application. METHODS: A survey was distributed to parents of patients with epilepsy aged 1 month to 19 years at British Columbia Children's Hospital. Following chart review, univariate and multivariate analyses were performed to identify variables that predict whether patients have SAPs. A systematic search of available mobile applications for epilepsy management was conducted. RESULTS: Of 192 participants, 62% have SAPs. On univariate analysis, history of prior SE and male gender increased likelihood of SAP. On logistic regression, Nagelkerke R2 was 0.204 and our model correctly predicted 82% of patients with SAPs. 83% of parents were interested in a SAP mobile application. There are currently 40 mobile applications available for epilepsy management, but only 15% of respondents reported using them. CONCLUSIONS: There is a need to increase the percentage of patients with epilepsy with SAPs, particularly in those at greater risk of SE. Most parents would find a SAP mobile application valuable in their child's epilepsy management. There is a gap between the high parental interest in mobile applications for epilepsy management and their current use of such applications.

Novel Neurotechnological Interventions for Pediatric Drug-Resistant Epilepsy: Physician Perspectives.

This qualitative study investigated factors that guide physicians' choices for minimally invasive and neuromodulatory interventions as alternatives to conventional surgery or medical management for pediatric drug-resistant epilepsy. North American physicians were recruited to one of 4 focus groups at national conferences. Discussions were analyzed using qualitative content analysis. A pragmatic neuroethics framework was applied to interpret results. Discussions revealed 2 major thematic branches: (1) clinical decision making and (2) ethical considerations. Under clinical decision making, physicians emphasized scientific evidence and patient candidacy when assessing neurotechnologies for patients. Ongoing seizures without intervention was important for safety and neurodevelopment. Under ethical considerations, resource allocation, among other financial considerations for technology adoption, were considerable sources of pressure on decision making. Access to neurotechnology was a salient theme differentiating Canadian and American contexts. When assessing novel neurotechnological interventions for pediatric drug-resistant epilepsy, physicians balance clinical and ethical factors to guide decision making and best practice.

Rapid Implementation of Virtual Health in a Pediatric Neurology Practice During COVID-19.

During the COVID-19 pandemic, the Division of Neurology at BC Children's Hospital rapidly transitioned to almost exclusively virtual health. In April 2020, 96% of outpatient visits were done virtually (64%) or by telephone, and only 4.2% were in-person. Total clinic visit numbers were unchanged compared to previous months. Neurologists reported high satisfaction with the virtual history and overall assessment, while the physical examination was less reliable. Additional in-person visits were rarely required. Rapid, sustained adoption of virtual health is possible in a pediatric neurology setting, providing reliable care that is comparable to in-person consultations when physical distancing is necessary.

Youth Weigh In: Views on Advanced Neurotechnology for Drug-Resistant Epilepsy.

BACKGROUND: Epilepsy affects over 500,000 children in North America of whom 30% have drug-resistant epilepsy. Advancements with neurotechnologies show promising benefits, but the perceptions of these procedures by youth is unknown. METHODS: We conducted semistructured interviews with 10 youth in British Columbia, Canada who underwent procedures for drug-resistant epilepsy involving different forms of neurotechnology (subdural grids, vagus nerve stimulation, responsive neurostimulation). Interviews were analyzed using the constant comparative qualitative method. RESULTS: Four major thematic categories emerged from the interviews. Treatment values, impact of the disorder, personal context, and impact of neurotechnology. CONCLUSIONS: Besides the predictable goal of seizure reduction, a desire for autonomy and the importance of trust in the medical team emerged as dominant values within the 4 thematic categories that were explicit to the use of new neurotechnologies for the management of drug-resistant epilepsy.

Correction to: Pathophysiology of and therapeutic options for a GABRA1 variant linked to epileptic encephalopathy.

Following publication of the original article [1], the authors reported errors in Figure 4.

Pathophysiology of and therapeutic options for a GABRA1 variant linked to epileptic encephalopathy.

We report the identification of a de novo GABRA1 (R214C) variant in a child with epileptic encephalopathy (EE), describe its functional characterization and pathophysiology, and evaluate its potential therapeutic options. The GABRA1 (R214C) variant was identified using whole exome sequencing, and the pathogenic effect of this mutation was investigated by comparing wild-type (WT) α1 and R214C α1 GABAA receptor-expressing HEK cells. GABA-evoked currents in these cells were recorded using whole-cell, outside-out macro-patch and cell-attached single-channel patch-clamp recordings. Changes to surface and total protein expression levels of WT α1 and R214C α1 were quantified using surface biotinylation assay and western blotting, respectively. Finally, potential therapeutic options were explored by determining the effects of modulators, including diazepam, insulin, and verapamil, on channel gating and receptor trafficking of WT and R214C GABAA receptors. We found that the GABRA1 (R214C) variant decreased whole-cell GABA-evoked currents by reducing single channel open time and both surface and total GABAA receptor expression levels. The GABA-evoked currents in R214C GABAA receptors could only be partially restored with benzodiazepine (diazepam) and insulin. However, verapamil treatment for 24 h fully restored the function of R214C mutant receptors, primarily by increasing channel open time. We conclude that the GABRA1 (R214C) variant reduces channel activity and surface expression of mutant receptors, thereby contributing to the pathogenesis of genetic EE. The functional restoration by verapamil suggests that it is a potentially new therapeutic option for patients with the R214C variant and highlights the value of precision medicine in the treatment of genetic EEs.

Position Statement on the Use of Medical Cannabis for the Treatment of Epilepsy in Canada.

In Canada, recreational use of cannabis was legalized in October 2018. This policy change along with recent publications evaluating the efficacy of cannabis for the medical treatment of epilepsy and media awareness about its use have increased the public interest about this agent. The Canadian League Against Epilepsy Medical Therapeutics Committee, along with a multidisciplinary group of experts and Canadian Epilepsy Alliance representatives, has developed a position statement about the use of medical cannabis for epilepsy. This article addresses the current Canadian legal framework, recent publications about its efficacy and safety profile, and our understanding of the clinical issues that should be considered when contemplating cannabis use for medical purposes.

Énoncé de position quant à l'utilisation du cannabis médical dans le traitement de l'épilepsie. L'utilisation du cannabis à des fins récréatives a été légalisée au Canada en octobre 2018. Parallèlement à ce changement de politique, de récentes publication visant à évaluer l'efficacité du cannabis dans le traitement de l'épilepsie, de même qu'une sensibilisation médiatique accrue en ce qui concerne son utilisation, ont eu pour effet d'augmenter l'intérêt du grand public à son égard. Le Comité médical thérapeutique de la Ligue canadienne contre l'épilepsie (LCCE), de concert avec un groupe multidisciplinaire d'experts et des représentants de l'Alliance canadienne de l'épilepsie, a ainsi élaboré un énoncé de position en ce qui regarde l'utilisation du cannabis médical dans le traitement de l'épilepsie. Cet article entend donc aborder le cadre légal qui prévaut actuellement au Canada et examiner de récentes publications s'étant penchées sur le profil sécuritaire et sur l'efficacité du cannabis. De plus, nous voulons apporter un éclairage au sujet des aspects cliniques dont il faudrait tenir compte au moment d'envisager l'utilisation du cannabis à des fins médicales.

Diagnostic Yield and Treatment Impact of Targeted Exome Sequencing in Early-Onset Epilepsy.

Targeted whole-exome sequencing (WES) is a powerful diagnostic tool for a broad spectrum of heterogeneous neurological disorders. Here, we aim to examine the impact on diagnosis, treatment and cost with early use of targeted WES in early-onset epilepsy. WES was performed on 180 patients with early-onset epilepsy (≤5 years) of unknown cause. Patients were classified as Retrospective (epilepsy diagnosis >6 months) or Prospective (epilepsy diagnosis <6 months). WES was performed on an Ion Proton™ and variant reporting was restricted to the sequences of 620 known epilepsy genes. Diagnostic yield and time to diagnosis were calculated. An analysis of cost and impact on treatment was also performed. A molecular diagnoses (pathogenic/likely pathogenic variants) was achieved in 59/180 patients (33%). Clinical management changed following WES findings in 23 of 59 diagnosed patients (39%) or 13% of all patients. A possible diagnosis was identified in 21 additional patients (12%) for whom supporting evidence is pending. Time from epilepsy onset to a genetic diagnosis was faster when WES was performed early in the diagnostic process (mean: 145 days Prospective vs. 2,882 days Retrospective). Costs of prior negative tests averaged $8,344 per patient in the Retrospective group, suggesting savings of $5,110 per patient using WES. These results highlight the diagnostic yield, clinical utility and potential cost-effectiveness of using targeted WES early in the diagnostic workup of patients with unexplained early-onset epilepsy. The costs and clinical benefits are likely to continue to improve. Advances in precision medicine and further studies regarding impact on long-term clinical outcome will be important.

Exome sequencing identified a de novo mutation of PURA gene in a patient with familial Xp22.31 microduplication.

The clinical significance of Xp22.31 microduplication is controversial as it is reported in subjects with developmental delay (DD), their unaffected relatives and unrelated controls. We performed multifaceted studies in a family of a boy with hypotonia, dysmorphic features and DD who carried a 600 Kb Xp22.31 microduplication (7515787-8123310bp, hg19) containing two genes, VCX and PNPLA4. The duplication was transmitted from his cognitively normal maternal grandfather. We found no evidence of the duplication causing the proband's DD and congenital anomalies based on unaltered expression of PNPLA4 in the proband and his mother in comparison to controls and preferential activation of the paternal chromosome X with Xp22.31 duplication in proband's mother. However, a de novo, previously reported deleterious, missense mutation in Pur-alpha gene (PURA) (5q31.2), with a role in neuronal differentiation was detected in the proband by exome sequencing. We propose that the variability in the phenotype in carriers of Xp22.31 microduplication can be due to a second and more deleterious genetic mutation in more severely affected carriers. Widespread use of whole genome next generation sequencing in families with Xp22.31 CNV could help identify such cases.