Genomic answers for children: Dynamic analyses of >1000 pediatric rare disease genomes.

PURPOSE: This study aimed to provide comprehensive diagnostic and candidate analyses in a pediatric rare disease cohort through the Genomic Answers for Kids program. METHODS: Extensive analyses of 960 families with suspected genetic disorders included short-read exome sequencing and short-read genome sequencing (srGS); PacBio HiFi long-read genome sequencing (HiFi-GS); variant calling for single nucleotide variants (SNV), structural variant (SV), and repeat variants; and machine-learning variant prioritization. Structured phenotypes, prioritized variants, and pedigrees were stored in PhenoTips database, with data sharing through controlled access the database of Genotypes and Phenotypes. RESULTS: Diagnostic rates ranged from 11% in patients with prior negative genetic testing to 34.5% in naive patients. Incorporating SVs from genome sequencing added up to 13% of new diagnoses in previously unsolved cases. HiFi-GS yielded increased discovery rate with >4-fold more rare coding SVs compared with srGS. Variants and genes of unknown significance remain the most common finding (58% of nondiagnostic cases). CONCLUSION: Computational prioritization is efficient for diagnostic SNVs. Thorough identification of non-SNVs remains challenging and is partly mitigated using HiFi-GS sequencing. Importantly, community research is supported by sharing real-time data to accelerate gene validation and by providing HiFi variant (SNV/SV) resources from >1000 human alleles to facilitate implementation of new sequencing platforms for rare disease diagnoses.

Combined use of the ketogenic diet and vagus nerve stimulation in pediatric drug-resistant epilepsy.

Objective: Patients with drug-resistant epilepsy (DRE) pose considerable management challenges for patients, their families, and providers. Both the vagus nerve stimulator (VNS) and the ketogenic diet (KD) have been shown to be safe and effective in treating DRE. Nevertheless, information is lacking regarding treatment with combination of both modalities. This study reports the efficacy and tolerability of combining VNS and KD in a pediatric cohort with intractable epilepsy. Methods: This is a retrospective review of 33 patients (0-17 years) with DRE treated with VNS and KD at a single pediatric level IV epilepsy center. We compared seizure reduction rates for each patient at baseline and at every clinic visit for 24 months after adding the second nonpharmacological therapy. The frequency of adverse events on the combined therapy was collected to assess safety and tolerability. Results: There were a total of 170 visits for all patients while on the combined therapy. At 88% (95% CI: 83%-93%) of the visits, patients reported some reduction in seizure frequency. The proportion of patients reporting a greater than 50% seizure reduction over all visits was 62% (95% CI: 55%-69%). The proportion of a patient's visits with at least a greater than 50% reduction in seizure frequency had a median of 71% (IQR 33%-100%). Continued improvement was seen over time of combined treatment; for every one-unit time unit change (one month), there was a 6% increase in the odds of having a reduction in seizure frequency of >50% (OR = 1.06, 95% CI: 1.01-1.11). Significance: This study shows that combining the VNS and KD in patients with drug-resistant epilepsy is well tolerated and reduces seizure frequency more than either one modality used alone and that the benefits in terms of seizure reduction continue to increase with the length of treatment.

Safety and tolerability of adjunctive lacosamide in a pediatric population with focal seizures - An open-label trial.

PURPOSE: To evaluate safety and tolerability of adjunctive lacosamide in children with focal seizures. METHODS: Patients were eligible for this open-label, fixed-titration trial (SP0847; NCT00938431) if aged 1 month-17 years with focal seizures taking 1-3 antiepileptic drugs. Findings from Cohort 1, aged 5-11 years, who received lacosamide ≤8 mg/kg/day, informed dosing for age-based cohorts 2-5, who then received ≤12 mg/kg/day (≤600 mg/day). Oral lacosamide was initiated at 2 mg/kg/day (1 mg/kg bid) and uptitrated by 2 mg/kg/day/week to the maximum cohort-defined dose (maximum trial duration: 13 weeks). Patients who did not achieve the maximum cohort-defined dose were discontinued. RESULTS: Forty-seven patients (aged 6 months-≤17 years) enrolled (≥1 month-<4 years: n = 15; ≥4-<12 years: n = 23; ≥12-≤17 years: n = 9). 24/47 (51.1%) patients completed the trial at the maximum cohort-defined dose and 40/47 (85.1%) continued lacosamide in the extension trial. Treatment-emergent adverse events (TEAEs) were reported by 42/47 (89.4%) patients. The most common TEAEs (≥10% of patients) were vomiting (21.3%), diarrhea (14.9%), somnolence (12.8%), irritability, dizziness, and pyrexia (10.6% each). Twenty (42.6%) patients discontinued due to TEAEs, most commonly vomiting (8.5%), gait disturbance, dizziness, and somnolence (6.4% each). Six (12.8%) patients reported serious TEAEs, most commonly status epilepticus (3/47; 6.4%). CONCLUSION: This fixed-titration trial supports the safety of adjunctive lacosamide in children (aged 6 months-≤17 years) with focal seizures. The TEAE profile was generally consistent with that observed in trials in adults, and no new safety concerns were identified.

Effectiveness of exome and genome sequencing guided by acuity of illness for diagnosis of neurodevelopmental disorders.

Neurodevelopmental disorders (NDDs) affect more than 3% of children and are attributable to single-gene mutations at more than 1000 loci. Traditional methods yield molecular diagnoses in less than one-half of children with NDD. Whole-genome sequencing (WGS) and whole-exome sequencing (WES) can enable diagnosis of NDD, but their clinical and cost-effectiveness are unknown. One hundred families with 119 children affected by NDD received diagnostic WGS and/or WES of parent-child trios, wherein the sequencing approach was guided by acuity of illness. Forty-five percent received molecular diagnoses. An accelerated sequencing modality, rapid WGS, yielded diagnoses in 73% of families with acutely ill children (11 of 15). Forty percent of families with children with nonacute NDD, followed in ambulatory care clinics (34 of 85), received diagnoses: 33 by WES and 1 by staged WES then WGS. The cost of prior negative tests in the nonacute patients was $19,100 per family, suggesting sequencing to be cost-effective at up to $7640 per family. A change in clinical care or impression of the pathophysiology was reported in 49% of newly diagnosed families. If WES or WGS had been performed at symptom onset, genomic diagnoses may have been made 77 months earlier than occurred in this study. It is suggested that initial diagnostic evaluation of children with NDD should include trio WGS or WES, with extension of accelerated sequencing modalities to high-acuity patients.

Management of symptomatic cholelithiasis while on ketogenic diet: a case report.

INTRODUCTION: The ketogenic diet is a treatment modality used for patients with refractory epilepsy. Development of cholelithiasis while on the ketogenic diet is a potential side effect that has been described in the literature. There however have not been any reports on the outcomes of continuing the diet after cholecystectomy. PATIENT: We present a 5-year-old boy with history of pharmacologically intractable epilepsy that was well controlled on the ketogenic diet. He underwent laparoscopic cholecystectomy for the development of symptomatic cholelithiasis 12 months after the initiation of ketogenic diet for seizure control. RESULTS: Patient tolerated the surgery well and was able to continue the ketogenic diet postoperatively. DISCUSSION: There have been no reports describing the continuation of ketogenic diet after cholecystectomy. This child demonstrates the safety of the procedure and the ability to continue the ketogenic diet without further biliary or surgical complications.

15q11.2 proximal imbalances associated with a diverse array of neuropsychiatric disorders and mild dysmorphic features.

Deletion within the proximal region of chromosome 15q11.2 between breakpoints 1 and 2 (BP1-BP2) has been proposed to be a risk factor for intellectual disability, seizure, and schizophrenia. However, the clinical significance of its reciprocal duplication is not clearly defined yet. We evaluated 1654 consecutive pediatric patients with various neurological disorders by high-resolution microarray-based comparative genomic hybridization. We identified 21 patients carrying 15q11.2 BP1-BP2 deletion and 12 patients carrying 15q11.2 BP1-BP2 duplication in this cohort, which represent 1.27% (21/1,654) and 0.7% (12/1,654) of the patients analyzed, respectively. Approximately 87.5% of the patients carrying the deletion and 80% of the patients carrying the duplication have developmental delay or intellectual disability. Other recurrent clinical features in these patients include mild dysmorphic features, autistic spectrum disorders, and epilepsy. Our observations provide further evidence in favor of a strong association of 15q11.2 BP1-BP2 deletion with a variety of neuropsychiatric disorders. The diversity of clinical findings in these patients expands the phe-notypic spectrum of individuals carrying the deletion. In addition, possible etiological effects of 15q11.2 BP1-BP2 duplication in neuropsychiatric disorders are proposed.

1.39 Mb inherited interstitial deletion in 12p13.33 associated with developmental delay.

We identified a novel 1.39 Mb interstitial deletion of chromosome 12p13.33 in an 8 year-old Caucasian female propositus and her affected father and brother using microarray-based comparative genomic hybridization (aCGH). They share a history of developmental delay and staring episodes. The deleted region contains eight annotated genes (ERC1, FBXL14, WNT5B, ADIPOR2, CACNA2D4, LRTM2, DCP1B, and CACNA1C). Hemizygous deletions of ERC1, FBXL14, or WNT5B genes may be involved in the development of neurological disorders in these individuals. Furthermore, the centromeric breakpoint of the 1.39 Mb deleted region is the same as the centromeric breakpoint of a 2.3 Mb terminal deletion of 12p13.33 reported recently, indicating the presence of an unstable structure near the breakpoint facilitating recurrent genomic rearrangements.

Incidental neuroimaging findings in nonacute headache.

We studied the frequency and consequences of incidental neuroimaging findings in 400 otherwise healthy, nonacute pediatric headache patients through a retrospective, cross-sectional analysis. We excluded patients with currently recommended clinical criteria to consider diagnostic neuroimaging. We categorized neuroimaging results as normal, remarkable without clinical action, remarkable with clinical follow-up action, and abnormal. One hundred eighty-five of 400 patients (46%) had neuroimaging. Of these, 78.4% of neuroimaging studies were normal, and none was considered abnormal. Also, 21.5% had remarkable findings in the neuroradiology report. The frequency and types of all incidental findings were generally comparable to previous studies. One third of these patients received further consultation or neuroimaging because of incidental findings. In the evaluation of nonacute pediatric headache, overuse of neuroimaging leads to frequent discovery of incidental findings and increased testing. Individualized health care calls for physician-consumer discussions about current indications for neuroimaging, the general frequency of incidental findings, and potential difficulties in their interpretation.

Cerebral venous thrombosis after immune thrombocytopenic purpura and anti-D immune globulin therapy.

Cerebral venous thrombosis has multiple etiologies and a wide variety of clinical manifestations. This article reports on a young girl who developed cerebral venous thrombosis after intravenous anti-D immune globulin therapy for immune thrombocytopenic purpura. In this case, venous infarction was manifested by an unusual pattern of restricted diffusion limited to the corpus callosum. The cause of cerebral venous thrombosis in this patient may be related to both immune thrombocytopenia and immunoglobulin therapy.