Feasibility of newborn screening for pyridoxine-dependent epilepsy.

Background: Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is a developmental epileptic encephalopathy historically characterized by seizures that are resistant to antiseizure medications. Treatment with pyridoxine and lysine reduction therapies are associated with seizure control and improved developmental outcomes. In rare circumstances, patients have died prior to diagnosis and treatment with pyridoxine, and many patients are diagnosed after six months of age when lysine reduction therapies have limited efficacy.

Assessment of urinary 6-oxo-pipecolic acid as a biomarker for ALDH7A1 deficiency.

ALDH7A1 deficiency is an epileptic encephalopathy whose seizures respond to treatment with supraphysiological doses of pyridoxine. It arises as a result of damaging variants in ALDH7A1, a gene in the lysine catabolism pathway. α-Aminoadipic semialdehyde (α-AASA) and Δ-piperideine-6-carboxylate (P6C), which accumulate because of the block in the lysine pathway, are diagnostic biomarkers for this disorder.

Dietary management for pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency, a follow-on from the international consortium guidelines.

Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is a neurometabolic disorder in the lysine metabolism pathway. In 2014 and 2021, the International PDE consortium published consensus guidelines about diagnosis and management. In this follow-on, a literature review was performed and nutrition management was evaluated through an international dietary questionnaire with 40 respondents.

Defining critical educational components of informed consent for genetic testing: views of US-based genetic counselors and medical geneticists.

The Clinical Genome Resource (ClinGen) Consent and Disclosure Recommendation (CADRe) framework proposes that key components of informed consent for genetic testing can be covered with a targeted discussion for many conditions rather than a time-intensive traditional genetic counseling approach. We surveyed US genetics professionals (medical geneticists and genetic counselors) on their response to scenarios that proposed core informed consent concepts for clinical genetic testing developed in a prior expert consensus process. The anonymous online survey included responses to 3 (of 6 possible) different clinical scenarios that summarized the application of the core concepts.

Association Between Lysine Reduction Therapies and Cognitive Outcomes in Patients With Pyridoxine-Dependent Epilepsy.

Background And Objectives: Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is a developmental epileptic encephalopathy characterized by seizure improvement after pyridoxine supplementation. Adjunct lysine reduction therapies (LRTs) reduce the accumulation of putative neurotoxic metabolites with the goal to improve developmental outcomes. Our objective was to examine the association between treatment with LRTs and cognitive outcomes.

Clinical Reasoning: Pediatric Seizures of Unknown Cause.

We describe a neonate and a 14-month-old child presenting with seizures that were not (completely) controlled with antiepileptic medications. There were no signs of infection, and electrolytes and neuroimaging were normal. In the neonate, pyridoxine was administered followed by cessation of seizures, and a diagnosis of pyridoxine-dependent epilepsy (PDE-ALDH7A1, a neurometabolic disorder of lysine metabolism) was genetically confirmed.

Timing of therapy and neurodevelopmental outcomes in 18 families with pyridoxine-dependent epilepsy.

Background: Seventy-five percent of patients with pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency (PDE-ALDH7A1) suffer intellectual developmental disability despite pyridoxine treatment. Adjunct lysine reduction therapies (LRT), aimed at lowering putative neurotoxic metabolites, are associated with improved cognitive outcomes. However, possibly due to timing of treatment, not all patients have normal intellectual function.

A case for newborn screening for pyridoxine-dependent epilepsy.

Pyridoxine-dependent epilepsy due to mutations in (PDH-ALDH7A1) is a highly treatable developmental and epileptic encephalopathy. Pharmacologic doses of pyridoxine are associated with dramatic clinical seizure improvement, and most patients achieve adequate seizure control with pyridoxine alone. Unfortunately, some patients with PDE-ALDH7A1 have died prior to when the diagnosis was made and subsequent treatment with pyridoxine could be implemented, highlighting the importance of a timely diagnosis.

Defining the Critical Components of Informed Consent for Genetic Testing.

Purpose: Informed consent for genetic testing has historically been acquired during pretest genetic counseling, without specific guidance defining which core concepts are required.

Methods: The Clinical Genome Resource (ClinGen) Consent and Disclosure Recommendations Workgroup (CADRe) used an expert consensus process to identify the core concepts essential to consent for clinical genetic testing. A literature review identified 77 concepts that are included in informed consent for genetic tests.

REVIEW: Practical strategies to maintain anabolism by intravenous nutritional management in children with inborn metabolic diseases.

One of the most vital elements of management for patients with inborn errors of intermediary metabolism is the promotion of anabolism, the state in which the body builds new components, and avoidance of catabolism, the state in which the body breaks down its own stores for energy. Anabolism is maintained through the provision of a sufficient supply of substrates for energy, as well as critical building blocks of essential amino acids, essential fatty acids, and vitamins for synthetic function and growth. Patients with metabolic diseases are at risk for decompensation during prolonged fasting, which often occurs during illnesses in which enteral intake is compromised.

Application of a framework to guide genetic testing communication across clinical indications.

Background: Genetic information is increasingly relevant across healthcare. Traditional genetic counseling (GC) may limit access to genetic information and may be more information and support than some individuals need. We report on the application and clinical implications of a framework to consistently integrate genetics expertise where it is most useful to patients.

Genomic regions associated with microdeletion/microduplication syndromes exhibit extreme diversity of structural variation.

Segmental duplications (SDs) are a class of long, repetitive DNA elements whose paralogs share a high level of sequence similarity with each other. SDs mediate chromosomal rearrangements that lead to structural variation in the general population as well as genomic disorders associated with multiple congenital anomalies, including the 7q11.23 (Williams-Beuren Syndrome, WBS), 15q13.

Consensus guidelines for the diagnosis and management of pyridoxine-dependent epilepsy due to α-aminoadipic semialdehyde dehydrogenase deficiency.

Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability.

Development and application of an ethical framework for pediatric metabolic and bariatric surgery evaluation.

Background: As severe obesity continues to rise among youth, metabolic and bariatric surgery (MBS) will increasingly be used as a treatment of choice for durable weight loss and improvement of obesity-related complications. MBS for youth with intellectual and developmental disabilities (IDD) and for preadolescents has raised ethical questions.

Objectives: The purpose of this article is to present the creation and application of an ethical framework that supports why MBS should be considered in pediatrics based on the principle of justice without automatic exclusions.

Inconsistencies in the Nutrition Management of Glutaric Aciduria Type 1: An International Survey.

Glutaric aciduria type 1 (GA-1) is a cerebral organic aciduria characterized by striatal injury and progressive movement disorder. Nutrition management shifted from a general restriction of intact protein to targeted restriction of lysine and tryptophan. Recent guidelines advocate for a low-lysine diet using lysine-free, tryptophan-reduced medical foods.

Abnormal expression of GABA receptor subunits and hypomotility upon loss of in zebrafish.

We used whole-exome sequencing (WES) to determine the genetic etiology of a patient with a multi-system disorder characterized by a seizure phenotype. WES identified a heterozygous missense mutation in the gene (c.875C>T).

Pathogenic variants in SQOR encoding sulfide:quinone oxidoreductase are a potentially treatable cause of Leigh disease.

Hydrogen sulfide, a signaling molecule formed mainly from cysteine, is catabolized by sulfide:quinone oxidoreductase (gene SQOR). Toxic hydrogen sulfide exposure inhibits complex IV. We describe children of two families with pathogenic variants in SQOR.

Genetic Testing: Consent and Result Disclosure for Primary Care Providers.

Historically, both pretest and posttest genetic counseling has been standard of care for genetic testing. This model should be adapted for primary care providers (PCPs) willing to learn critical information about the test and key concepts that patients need to make an informed testing decision. It is helpful for PCPs to discuss a few initial patients with a genetic counselor to prepare for the key concepts of pretest and posttest counseling.

The 22q11 low copy repeats are characterized by unprecedented size and structural variability.

Low copy repeats (LCRs) are recognized as a significant source of genomic instability, driving genome variability and evolution. The Chromosome 22 LCRs (LCR22s) mediate nonallelic homologous recombination (NAHR) leading to the 22q11 deletion syndrome (22q11DS). However, LCR22s are among the most complex regions in the genome, and their structure remains unresolved.

Developing interactions with industry in rare diseases: lessons learned and continuing challenges.

The National Institutes of Health (NIH) established the Rare Diseases Clinical Research Network to address the unique challenges of performing research on rare diseases. The Urea Cycle Disorders Consortium (UCDC) was one of the original ten consortia established. The UCDC represents a unique partnership among clinicians, patients, and the NIH with a primary goal of increasing the development of therapeutics that improve patient outcomes for persons affected with a UCD.

Brain imaging in classic nonketotic hyperglycinemia: Quantitative analysis and relation to phenotype.

Patients with severe nonketotic hyperglycinemia (NKH) have absent psychomotor development and intractable epilepsy, whereas attenuated patients have variable psychomotor development and absent or treatable epilepsy; differences in brain magnetic resonance imaging (MRI) between phenotypes have not been reported. In a retrospective cross-sectional study, we reviewed 38 MRI studies from 24 molecularly proven NKH patients, and 2 transient NKH patients. Quantitative analyses included corpus callosum size, apparent diffusion coefficient, automated brain volumetric analysis, and glycine/creatine ratio by spectroscopy.

Identification of a novel biomarker for pyridoxine-dependent epilepsy: Implications for newborn screening.

Pyridoxine-dependent epilepsy (PDE) is often characterized as an early onset epileptic encephalopathy with dramatic clinical improvement following pyridoxine supplementation. Unfortunately, not all patients present with classic neonatal seizures or respond to an initial pyridoxine trial, which can result in the under diagnosis of this treatable disorder. Restriction of lysine intake and transport is associated with improved neurologic outcomes, although treatment should be started in the first year of life to be effective.