Late-Onset Multiple Acyl-CoA Dehydrogenase Deficiency Presenting as Hyperammonemia and Encephalopathy: Case Series.

Multiple acyl-CoA dehydrogenase deficiency (MADD) is an inherited metabolic disorder (IMD) that affects the electron transfer chain and fatty acid oxidation. The late-onset form of MADD has a heterogenous clinical presentation that typically results in episodic lethargy, hypoglycemia, acidosis, and rhabdomyolysis during metabolic decompensations. In this case report series we describe three cases of late-onset MADD presenting with hyperammonemia and encephalopathy, a less frequent but severe complication.

Genetic counselors' perspectives on genomic screening of apparently healthy newborns in the United States.

Purpose: There is growing international interest in using genomic sequencing to screen newborns and children for treatable genomic conditions. Although recent research has demonstrated increasing support for using genomic sequencing to screen newborns and children for treatable genomic conditions among various stakeholders, little is known about the perspectives of genetic counselors (GCs) in the United States, who are frequently engaged in the disclosure of positive newborn screening results and coordination of follow-up testing and management.

Methods: This study utilized a cross-sectional 3-section survey to explore GCs' perspectives on the benefits, limitations, and ethical and practical considerations of genomic sequencing in newborns as an adjunct screen to standard newborn screening (NBS).

Executive and adaptive function impacts long-term outcomes for adults with maple syrup urine disease.

Successful transition to independent adulthood requires intact executive and adaptive function. These neurocognitive domains are frequently impaired in inherited metabolic disorders (IMD), despite optimal management. For many IMDs, the impact of executive and adaptive dysfunction on long-term outcomes remains undefined.

Long-Term Health Outcomes of Individuals With Pseudodeficiency Alleles in IDUA May Inform Newborn Screening Practices for Mucopolysaccharidosis Type I.

Mucopolysaccharidosis type I (MPS I), a lysosomal disorder caused by variants in IDUA, was added to the Recommended Uniform Screening Panel for newborn screening in 2016. Positive screening results for MPS I are commonly due to variants known as "pseudodeficiency alleles," which decrease in vitro alpha-L-iduronidase enzyme activity but are thought to provide sufficient in vivo activity. Despite the historic assumption that these variants are biologically benign, the possibility that they could give rise to complex, multigenic, or attenuated phenotypes has not been systemically evaluated in adults.

Upregulation versus loss of function of NTRK2 in 44 affected individuals leads to 2 distinct neurodevelopmental disorders.

Purpose: Heterozygous pathogenic variants in NTRK2 (HGNC: 8032) have been associated with global developmental delay. However, only scattered cases have been described in small or general studies. The aim of our work was to consolidate our understanding of NTRK2-related disorders and to delineate the clinical presentation.

Preferences of parents from diverse backgrounds on genomic screening of apparently healthy newborns.

Genomic sequencing has been proposed as a strategy to expand newborn screening. Perspectives on genomic newborn screening from parents of diverse racial, ethnic, and socioeconomic backgrounds are needed to shape equitable implementation of this modality. We conducted 20 semi-structured interviews (15 English, 5 Spanish) and seven focus groups (4 English, 3 Spanish) with parents from diverse backgrounds to assess their perspectives regarding which disorders and variants might be screened, data privacy, and barriers to pursuing specialized care.

Diverse Participant Recruitment for Infant Sequencing in the BabySeq Project.

Purpose: It is essential that studies of genomic sequencing (GS) in newborns and children include individuals from under-represented racial and ethnic groups (URG) to ensure future applications are equitably implemented. We conducted interviews with parents from URG to better understand their perspectives on GS research, develop strategies to reduce barriers to enrollment, and facilitate research participation.

Methods: Semi-structured interviews with 50 parents from URG.

The BabySeq Project: A clinical trial of genome sequencing in a diverse cohort of infants.

Efforts to implement and evaluate genome sequencing (GS) as a screening tool for newborns and infants are expanding worldwide. The first iteration of the BabySeq Project (2015-2019), a randomized controlled trial of newborn sequencing, produced novel evidence on medical, behavioral, and economic outcomes. The second iteration of BabySeq, which began participant recruitment in January 2023, examines GS outcomes in a larger, more diverse cohort of more than 500 infants up to one year of age recruited from pediatric clinics at several sites across the United States.

Data-driven prioritization of genetic disorders for global genomic newborn screening programs.

Genomic sequencing is poised to expand newborn screening for treatable childhood-onset disorders. Over 30 international research studies and companies are exploring its use, collectively aiming to screen more than 500,000 infants. A key challenge is determining which genes to include in screening.

Variants in ZFX are associated with an X-linked neurodevelopmental disorder with recurrent facial gestalt.

Pathogenic variants in multiple genes on the X chromosome have been implicated in syndromic and non-syndromic intellectual disability disorders. ZFX on Xp22.11 encodes a transcription factor that has been linked to diverse processes including oncogenesis and development, but germline variants have not been characterized in association with disease.

variants underlying X-linked intellectual disability disrupt protein function via distinct mechanisms.

Neurodevelopmental disorders with intellectual disability (ND/ID) are a heterogeneous group of diseases driving lifelong deficits in cognition and behavior with no definitive cure. X-linked intellectual disability disorder 105 (XLID105, #300984; OMIM) is a ND/ID driven by hemizygous variants in the gene encoding a protein deubiquitylase with a role in cell proliferation and neural development. Currently, only four genetically diagnosed individuals from two unrelated families have been described with limited clinical data.

Endocrine features of primary mitochondrial diseases.

Purpose Of Review: Primary mitochondrial diseases are one of the most prevalent groups of multisystem genetic disorders. Endocrinopathies associated with mitochondrial diseases may have clinical features that are distinct from the more common forms. We provide an overview of mitochondrial disorder genetics and phenotypes, focusing on recent studies regarding identification and treatment of associated endocrinopathies.

Phenotypes of undiagnosed adults with actionable and variants.

Inherited metabolic disorders (IMDs) are variably expressive, complicating identification of affected individuals. A genotype-first approach can identify individuals at risk for morbidity and mortality from undiagnosed IMDs and can lead to protocols that improve clinical detection, counseling, and management. Using data from 57,340 participants in two hospital biobanks, we assessed the frequency and phenotypes of individuals with pathogenic/likely pathogenic variants (PLPVs) in two IMD genes: , associated with Fabry disease, and , associated with ornithine transcarbamylase deficiency.

Perspectives of Rare Disease Experts on Newborn Genome Sequencing.

Importance: Newborn genome sequencing (NBSeq) can detect infants at risk for treatable disorders currently undetected by conventional newborn screening. Despite broad stakeholder support for NBSeq, the perspectives of rare disease experts regarding which diseases should be screened have not been ascertained.

Objective: To query rare disease experts about their perspectives on NBSeq and which gene-disease pairs they consider appropriate to evaluate in apparently healthy newborns.

Implications of Genomic Newborn Screening for Infant Mortality.

Technological advances and decreasing costs of genomic sequencing have paved the way for the increased incorporation of genomics into newborn screening (NBS). Genomic sequencing may complement current NBS laboratory analyses or may be used as a first-tier screening tool to identify disorders not detected by current approaches. As a large proportion of infant deaths occur in children with an underlying genetic disorder, earlier diagnosis of these disorders may improve neonatal and infant mortality rates.

When is the best time to screen and evaluate for treatable genetic disorders?: A lifespan perspective.

This paper focuses on the question of, "When is the best time to identify an individual at risk for a treatable genetic condition?" In this review, we describe a framework for considering the optimal timing for pursuing genetic and genomic screening for treatable genetic conditions incorporating a lifespan approach. Utilizing the concept of a carousel that represents the four broad time periods when critical decisions might be made around genetic diagnoses during a person's lifetime, we describe genetic testing during the prenatal period, the newborn period, childhood, and adulthood. For each of these periods, we describe the objectives of genetic testing, the current status of screening or testing, the near-term vision for the future of genomic testing, the advantages and disadvantages of each approach, and the feasibility and ethical considerations of testing and treating.

Are we prepared to deliver gene-targeted therapies for rare diseases?

The cost and time needed to conduct whole-genome sequencing (WGS) have decreased significantly in the last 20 years. At the same time, the number of conditions with a known molecular basis has steadily increased, as has the number of investigational new drug applications for novel gene-based therapeutics. The prospect of precision gene-targeted therapy for all seems in reach… or is it? Here we consider practical and strategic considerations that need to be addressed to establish a foundation for the early, effective, and equitable delivery of these treatments.

The current state of adult metabolic medicine in the United States: Results of a nationwide survey.

Purpose: Patients with inherited metabolic disorders (IMDs) now have improved health outcomes and increased survival into adulthood. There is scant evidence on managing adults with IMDs. We present an analysis of current care practices for adults with IMDs in the United States.