Selected Grantee Publications
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- 9 results found
- Rare Diseases
- 2025
- 2022
De Novo and Inherited Variants in DDX39B Cause a Novel Neurodevelopmental Syndrome
Booth et al., Brain. 2025.
https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awaf035/8004980?login=true
DDX39B is a core component of the TRanscription-EXport (TREX) super protein complex. Recent studies have highlighted the important role of TREX subunits in neurodevelopmental disorders. Researchers describe a cohort of six individuals (male and female) from five families with disease-causing de novo missense variants or inherited splice-altering variants in DDX39B. Three individuals in the cohort are affected by mild to severe developmental delay, hypotonia, history of epilepsy or seizure, short stature, skeletal abnormalities, variable dysmorphic features, and microcephaly. Using a combination of patient genomic and transcriptomic data, in silico modeling, in vitro assays, and in vivo Drosophila and zebrafish models, this study implicates disruption of DDX39B in a novel neurodevelopmental disorder called TREX-complex-related neurodevelopmental syndrome. Supported by ORIP (U54OD030165).
Dysregulation of mTOR Signalling Is a Converging Mechanism in Lissencephaly
Zhang et al., Nature. 2025.
https://pubmed.ncbi.nlm.nih.gov/39743596
Lissencephaly (smooth brain) is a rare genetic condition, with such symptoms as epilepsy and intellectual disability and a median life expectancy of 10 years. This study reveals that reduced activity of the mTOR pathway may be a common cause of lissencephaly. Researchers used laboratory-grown brain models (organoids) and sequencing and spectrometry techniques to identify decreased mTOR activation in two types of lissencephaly disorders: p53-induced death domain protein 1 and Miller–Dieker lissencephaly syndrome. Pharmacological activation of mTOR signaling with a brain-selective mTORC1 activator molecule, NV-5138, prevented and reversed the morphological and functional defects in organoids. These findings suggest that mTOR dysregulation contributes to the development of lissencephaly spectrum disorders and highlight a potential druggable pathway for therapy. Supported by ORIP (S10OD018034, S10OD019967, S10OD030363), NCATS, NHGRI, NICHD, NIDA, NIGMS, NIMH, and NINDS.
Establishing the Hybrid Rat Diversity Program: A Resource for Dissecting Complex Traits
Dwinell et al., Mammalian Genome. 2025.
https://pubmed.ncbi.nlm.nih.gov/39907792
Rat models have been extensively used for studying human complex disease mechanisms, behavioral phenotypes, and environmental factors and for discovering and developing drugs. Systems genetics approaches have been used to study the effects of both genetic variation and environmental factors. This approach recognizes the complexity of common disorders and uses intermediate phenotypes to find relationships between genetic variation and clinical traits. This article describes the Hybrid Rat Diversity Program (HDRP) at the Medical College of Wisconsin, which involves 96 inbred rat strains and aims to provide a renewable and reusable resource in terms of the HRDP panel of inbred rat strains, the genomic data derived from the HRDP strains, and banked resources available for additional studies. Supported by ORIP (R24OD024617) and NHLBI.
Preclinical Use of a Clinically-Relevant scAAV9/SUMF1 Vector for the Treatment of Multiple Sulfatase Deficiency
Presa et al., Communications Medicine. 2025.
https://pubmed.ncbi.nlm.nih.gov/39870870
This study evaluates a gene therapy strategy using an adeno-associated virus (AAV)/SUMF1 vector to treat multiple sulfatase deficiency (MSD), a rare and fatal lysosomal storage disorder caused by mutations in the SUMF1 gene. Researchers delivered the functional gene to male and female Sumf1 knockout mice either neonatally or after symptom onset. Neonatal treatment via cerebral spinal fluid extended survival up to 1 year, alleviated MSD symptoms, and restored normal behavior and cardiac and visual function without toxicity. Treated tissues showed widespread SUMF1 expression and enzymatic activity. These findings support the translational potential of this gene replacement therapy for clinical use in MSD patients. Supported by ORIP (U42OD010921, U54OD020351, U54OD030187) and NCI.
Plural Molecular and Cellular Mechanisms of Pore Domain KCNQ2 Encephalopathy
Abreo et al., eLife. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11703504
This study investigates the cellular and molecular mechanisms underlying KCNQ2 encephalopathy, a severe type of early-onset epilepsy caused by mutations in the KCNQ2 gene. Researchers describe a case study of a child with a specific KCNQ2 gene mutation, G256W, and found that it disrupts normal brain activity, leading to seizures and developmental impairments. Male and female Kcnq2G256W/+ mice have reduced KCNQ2 protein levels, epilepsy, brain hyperactivity, and premature deaths. As seen in the patient study, ezogabine treatment rescued seizures in mice, suggesting a potential treatment avenue. These findings provide important insights into KCNQ2-related epilepsy and highlight possible therapeutic strategies. Supported by ORIP (U54OD020351, S10OD026804, U54OD030187), NCI, NHLBI, NICHD, NIGMS, NIMH, and NINDS.
Mendelian Gene Identification through Mouse Embryo Viability Screening
Cacheiro et al., Genome Medicine. 2022.
https://www.doi.org/10.1186/s13073-022-01118-7
The investigators dissected phenotypic similarities between patients and model organisms by assessing the embryonic stage at which homozygous loss of function results in lethality in mice of both sexes obtained from the International Mouse Phenotyping Consortium. Information on knockout mouse embryo lethality can be used to prioritize candidate genes associated with certain disorders. Access to unsolved cases from rare-disease genome sequencing programs allows for the screening of those genes for potentially pathogenic variants, which could lead to a diagnosis and new potential treatment options to inform the management of human disease. Supported by ORIP (UM1OD023221, UM1OD023222, U42OD011174) and NHGRI.
De Novo Variants in EMC1 Lead to Neurodevelopmental Delay and Cerebellar Degeneration and Affect Glial Function in Drosophila
Chung et al., Human Molecular Genetics. 2022.
https://www.doi.org/10.1093/hmg/ddac053
Variants in EMC1, which encodes a subunit of the endoplasmic reticulum (ER)–membrane protein complex (EMC), are associated with developmental delay in children. Functional consequences of these variants are poorly understood. The investigators identified de novo variants in EMC1 in three children affected by global developmental delay, hypotonia, seizures, visual impairment, and cerebellar atrophy. They demonstrated in Drosophila that these variants are loss-of-function alleles and lead to lethality when expressed in glia but not in neurons. This work suggests the causality of EMC variants in disease. Supported by ORIP (R24OD022005, R24OD031447), NINDS, and NICHD.
Sunitinib Inhibits STAT3 Phosphorylation in Cardiac Muscle and Prevents Cardiomyopathy in the mdx Mouse Model of Duchenne Muscular Dystrophy
Oliveira-Santos et al., Human Molecular Genetics. 2022.
https://www.doi.org/10.1093/hmg/ddac042
Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy, affecting about 1 in 5,000 boys worldwide. DMD is a fatal X-linked genetic disorder that results from mutations in the dystrophin gene and leads to progressive muscular degeneration. Individuals with DMD often die at a young age from respiratory or heart failure. To date, few studies have examined the basis of cardiac failure associated with DMD, and no effective U.S. Food and Drug Administration (FDA)–approved treatment options are available. Using a mouse model of both sexes, researchers characterized the effectiveness of sunitinib, an FDA-approved small-molecule drug, in preventing DMD-related cardiomyopathy. The treatment reduced STAT3 activation in cardiac muscle and prevented cardiomyopathy disease progression. Inhibition of STAT3 activation in cardiac muscle can reduce inflammation and fibrosis and prevent heart failure. These findings demonstrate sunitinib’s potential as a novel treatment option for skeletal and cardiac muscle dysfunction in patients with DMD. Supported by ORIP (R42OD030543).
A Novel DPH5-Related Diphthamide-Deficiency Syndrome Causing Embryonic Lethality or Profound Neurodevelopmental Disorder
Shankar et al., Genetics in Medicine. 2022.
https://www.doi.org/10.1016/j.gim.2022.03.014
Neurodevelopmental disorders (NDDs) affect more than 3% of the pediatric population and often have associated neurologic or multisystem involvement. The underlying genetic etiology of NDDs remains unknown in many individuals. Investigators characterized the molecular basis of NDDs in children of both sexes with nonverbal NDDs from three unrelated families with distinct overlapping craniofacial features. The investigators also used a mouse model of both sexes to determine the pathogenicity of variants of uncertain significance, as well as genes of uncertain significance, to advance translational genomics and provide precision health care. They identified several variants in DPH5 as a potential cause of profound NDD. Their findings provide strong clinical, biochemical, and functional evidence for DPH5 variants as a novel cause of embryonic lethality or profound NDD with multisystem involvement. Based on these findings, the authors propose that “DPH5-related diphthamide deficiency syndrome” is a novel autosomal-recessive Mendelian disorder. Supported by ORIP (K01OD026608, U42OD012210) and NHGRI.