Moderate- Probability Risk ASD Gene Set. Table of 292 genes from AutDB categorized as possibly da... more Moderate- Probability Risk ASD Gene Set. Table of 292 genes from AutDB categorized as possibly damaging and included as moderate-risk ASD gene set. (XLS 151Â kb)
Assessing cognitive abilities in children is challenging for two primary reasons: lack of testing... more Assessing cognitive abilities in children is challenging for two primary reasons: lack of testing engagement can lead to low testing sensitivity and inherent performance variability. Here we sought to explore whether an engaging, adaptive digital cognitive platform built to look and feel like a video game would reliably measure attention-based abilities in children with and without neurodevelopmental disabilities related to a known genetic condition, 16p11.2 deletion. We assessed 20 children with 16p11.2 deletion, a genetic variation implicated in attention deficit/hyperactivity disorder and autism, as well as 16 siblings without the deletion and 75 neurotypical age-matched children. Deletion carriers showed significantly slower response times and greater response variability when compared with all non-carriers; by comparison, traditional non-adaptive selective attention assessments were unable to discriminate group differences. This phenotypic characterization highlights the potent...
Genome sequencing (GS) is promising for unsolved leukodystrophies, but its efficacy has not been ... more Genome sequencing (GS) is promising for unsolved leukodystrophies, but its efficacy has not been prospectively studied.
BackgroundO’Donnell-Luria-Rodan syndrome (ODLURO) is an autosomal-dominant neurodevelopmental dis... more BackgroundO’Donnell-Luria-Rodan syndrome (ODLURO) is an autosomal-dominant neurodevelopmental disorder caused by pathogenic, mostly truncating variants in KMT2E. It was first described by O’Donnell-Luria et al in 2019 in a cohort of 38 patients. Clinical features encompass macrocephaly, mild intellectual disability (ID), autism spectrum disorder (ASD) susceptibility and seizure susceptibility.MethodsAffected individuals were ascertained at paediatric and genetic centres in various countries by diagnostic chromosome microarray or exome/genome sequencing. Patients were collected into a case cohort and were systematically phenotyped where possible.ResultsWe report 18 additional patients from 17 families with genetically confirmed ODLURO. We identified 15 different heterozygous likely pathogenic or pathogenic sequence variants (14 novel) and two partial microdeletions of KMT2E. We confirm and refine the phenotypic spectrum of the KMT2E-related neurodevelopmental disorder, especially con...
Agenesis of the corpus callosum (ACC), a failure of the corpus callosum to develop, is linked to ... more Agenesis of the corpus callosum (ACC), a failure of the corpus callosum to develop, is linked to over 50 congenital syndromes. One syndrome which exhibits ACC as a symptom is Temtamy Syndrome, whic...
High- Probability Risk ASD Gene Set. Table of seventy-six genes from AutDB determined to be â pro... more High- Probability Risk ASD Gene Set. Table of seventy-six genes from AutDB determined to be â probably damagingâ and included in the high-risk ASD gene set. (XLS 80Â kb)
Corpus callosum dysgenesis (CCD) is a congenital disorder that incorporates either partial or com... more Corpus callosum dysgenesis (CCD) is a congenital disorder that incorporates either partial or complete absence of the largest cerebral commissure. Remodelling of the interhemispheric fissure (IHF) provides a substrate for callosal axons to cross between hemispheres, and its failure is the main cause of complete CCD. However, it is unclear whether defects in this process could give rise to the heterogeneity of expressivity and phenotypes seen in human cases of CCD. We identify incomplete IHF remodelling as the key structural correlate for the range of callosal abnormalities in inbred and outcrossed BTBR mouse strains, as well as in humans with partial CCD. We identify an eight base-pair deletion in Draxin and misregulated astroglial and leptomeningeal proliferation as genetic and cellular factors for variable IHF remodelling and CCD in BTBR strains. These findings support a model where genetic events determine corpus callosum structure by influencing leptomeningeal-astroglial interac...
The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheri... more The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheric fissure (IHF). Radial astroglia remodel the IHF to form a continuous substrate between the hemispheres for midline crossing of the corpus callosum (CC) and hippocampal commissure (HC). DCC and NTN1 are molecules that have an evolutionarily conserved function in commissural axon guidance. The CC and HC are absent in Dcc and Ntn1 knockout mice, while other commissures are only partially affected, suggesting an additional aetiology in forebrain commissure formation. Here, we find that these molecules play a critical role in regulating astroglial development and IHF remodelling during CC and HC formation. Human subjects with DCC mutations display disrupted IHF remodelling associated with CC and HC malformations. Thus, axon guidance molecules such as DCC and NTN1 first regulate the formation of a midline substrate for dorsal commissures prior to their role in regulating axonal growth and gu...
The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheri... more The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheric fissure (IHF). Radial astroglia remodel the IHF to form a continuous substrate between the hemispheres for midline crossing of the corpus callosum (CC) and hippocampal commissure (HC). DCC and NTN1 are molecules that have an evolutionarily conserved function in commissural axon guidance. The CC and HC are absent in Dcc and Ntn1 knockout mice, while other commissures are only partially affected, suggesting an additional aetiology in forebrain commissure formation. Here, we find that these molecules play a critical role in regulating astroglial development and IHF remodelling during CC and HC formation. Human subjects with DCC mutations display disrupted IHF remodelling associated with CC and HC malformations. Thus, axon guidance molecules such as DCC and NTN1 first regulate the formation of a midline substrate for dorsal commissures prior to their role in regulating axonal growth and gu...
The deleted in colorectal cancer (DCC) gene encodes the netrin-1 receptor DCC, a transmembrane pr... more The deleted in colorectal cancer (DCC) gene encodes the netrin-1 receptor DCC, a transmembrane protein required for the guidance of commissural axons. Germline DCC mutations disrupt the development of predominantly commissural tracts in the central nervous system (CNS) and cause a spectrum of neurological disorders. Monoallelic, missense and predicted loss-of-function DCC mutations cause congenital mirror movements, isolated agenesis of the corpus callosum, or both. Biallelic, predicted loss-of-function DCC mutations cause developmental split brain syndrome. Although the underlying molecular mechanisms leading to disease remain poorly understood, they are thought to stem from reduced or perturbed Netrin-1 signaling. Here we review the 26 reported DCC mutations associated with abnormal CNS development in humans, including 14 missense and 12 predicted loss-of-function mutations, and discuss their associated clinical characteristics and diagnostic features. We provide an update on the ...
Moderate- Probability Risk ASD Gene Set. Table of 292 genes from AutDB categorized as possibly da... more Moderate- Probability Risk ASD Gene Set. Table of 292 genes from AutDB categorized as possibly damaging and included as moderate-risk ASD gene set. (XLS 151Â kb)
Assessing cognitive abilities in children is challenging for two primary reasons: lack of testing... more Assessing cognitive abilities in children is challenging for two primary reasons: lack of testing engagement can lead to low testing sensitivity and inherent performance variability. Here we sought to explore whether an engaging, adaptive digital cognitive platform built to look and feel like a video game would reliably measure attention-based abilities in children with and without neurodevelopmental disabilities related to a known genetic condition, 16p11.2 deletion. We assessed 20 children with 16p11.2 deletion, a genetic variation implicated in attention deficit/hyperactivity disorder and autism, as well as 16 siblings without the deletion and 75 neurotypical age-matched children. Deletion carriers showed significantly slower response times and greater response variability when compared with all non-carriers; by comparison, traditional non-adaptive selective attention assessments were unable to discriminate group differences. This phenotypic characterization highlights the potent...
Genome sequencing (GS) is promising for unsolved leukodystrophies, but its efficacy has not been ... more Genome sequencing (GS) is promising for unsolved leukodystrophies, but its efficacy has not been prospectively studied.
BackgroundO’Donnell-Luria-Rodan syndrome (ODLURO) is an autosomal-dominant neurodevelopmental dis... more BackgroundO’Donnell-Luria-Rodan syndrome (ODLURO) is an autosomal-dominant neurodevelopmental disorder caused by pathogenic, mostly truncating variants in KMT2E. It was first described by O’Donnell-Luria et al in 2019 in a cohort of 38 patients. Clinical features encompass macrocephaly, mild intellectual disability (ID), autism spectrum disorder (ASD) susceptibility and seizure susceptibility.MethodsAffected individuals were ascertained at paediatric and genetic centres in various countries by diagnostic chromosome microarray or exome/genome sequencing. Patients were collected into a case cohort and were systematically phenotyped where possible.ResultsWe report 18 additional patients from 17 families with genetically confirmed ODLURO. We identified 15 different heterozygous likely pathogenic or pathogenic sequence variants (14 novel) and two partial microdeletions of KMT2E. We confirm and refine the phenotypic spectrum of the KMT2E-related neurodevelopmental disorder, especially con...
Agenesis of the corpus callosum (ACC), a failure of the corpus callosum to develop, is linked to ... more Agenesis of the corpus callosum (ACC), a failure of the corpus callosum to develop, is linked to over 50 congenital syndromes. One syndrome which exhibits ACC as a symptom is Temtamy Syndrome, whic...
High- Probability Risk ASD Gene Set. Table of seventy-six genes from AutDB determined to be â pro... more High- Probability Risk ASD Gene Set. Table of seventy-six genes from AutDB determined to be â probably damagingâ and included in the high-risk ASD gene set. (XLS 80Â kb)
Corpus callosum dysgenesis (CCD) is a congenital disorder that incorporates either partial or com... more Corpus callosum dysgenesis (CCD) is a congenital disorder that incorporates either partial or complete absence of the largest cerebral commissure. Remodelling of the interhemispheric fissure (IHF) provides a substrate for callosal axons to cross between hemispheres, and its failure is the main cause of complete CCD. However, it is unclear whether defects in this process could give rise to the heterogeneity of expressivity and phenotypes seen in human cases of CCD. We identify incomplete IHF remodelling as the key structural correlate for the range of callosal abnormalities in inbred and outcrossed BTBR mouse strains, as well as in humans with partial CCD. We identify an eight base-pair deletion in Draxin and misregulated astroglial and leptomeningeal proliferation as genetic and cellular factors for variable IHF remodelling and CCD in BTBR strains. These findings support a model where genetic events determine corpus callosum structure by influencing leptomeningeal-astroglial interac...
The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheri... more The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheric fissure (IHF). Radial astroglia remodel the IHF to form a continuous substrate between the hemispheres for midline crossing of the corpus callosum (CC) and hippocampal commissure (HC). DCC and NTN1 are molecules that have an evolutionarily conserved function in commissural axon guidance. The CC and HC are absent in Dcc and Ntn1 knockout mice, while other commissures are only partially affected, suggesting an additional aetiology in forebrain commissure formation. Here, we find that these molecules play a critical role in regulating astroglial development and IHF remodelling during CC and HC formation. Human subjects with DCC mutations display disrupted IHF remodelling associated with CC and HC malformations. Thus, axon guidance molecules such as DCC and NTN1 first regulate the formation of a midline substrate for dorsal commissures prior to their role in regulating axonal growth and gu...
The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheri... more The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheric fissure (IHF). Radial astroglia remodel the IHF to form a continuous substrate between the hemispheres for midline crossing of the corpus callosum (CC) and hippocampal commissure (HC). DCC and NTN1 are molecules that have an evolutionarily conserved function in commissural axon guidance. The CC and HC are absent in Dcc and Ntn1 knockout mice, while other commissures are only partially affected, suggesting an additional aetiology in forebrain commissure formation. Here, we find that these molecules play a critical role in regulating astroglial development and IHF remodelling during CC and HC formation. Human subjects with DCC mutations display disrupted IHF remodelling associated with CC and HC malformations. Thus, axon guidance molecules such as DCC and NTN1 first regulate the formation of a midline substrate for dorsal commissures prior to their role in regulating axonal growth and gu...
The deleted in colorectal cancer (DCC) gene encodes the netrin-1 receptor DCC, a transmembrane pr... more The deleted in colorectal cancer (DCC) gene encodes the netrin-1 receptor DCC, a transmembrane protein required for the guidance of commissural axons. Germline DCC mutations disrupt the development of predominantly commissural tracts in the central nervous system (CNS) and cause a spectrum of neurological disorders. Monoallelic, missense and predicted loss-of-function DCC mutations cause congenital mirror movements, isolated agenesis of the corpus callosum, or both. Biallelic, predicted loss-of-function DCC mutations cause developmental split brain syndrome. Although the underlying molecular mechanisms leading to disease remain poorly understood, they are thought to stem from reduced or perturbed Netrin-1 signaling. Here we review the 26 reported DCC mutations associated with abnormal CNS development in humans, including 14 missense and 12 predicted loss-of-function mutations, and discuss their associated clinical characteristics and diagnostic features. We provide an update on the ...
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Papers by Elliott Sherr