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| Callosome v0.517 | SNF8 | Elena Savva Phenotypes for gene: SNF8 were changed from Severe developmental delay, epileptic encephalopathy, brain MRI abnormality; intellectual disability, childhood-onset optic atrophy, ataxia to Neurodevelopmental disorder (MONDO:0700092), SNF8-related | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Callosome v0.516 | SNF8 |
Chern Lim gene: SNF8 was added gene: SNF8 was added to Callosome. Sources: Literature Mode of inheritance for gene: SNF8 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SNF8 were set to 38423010 Phenotypes for gene: SNF8 were set to Severe developmental delay, epileptic encephalopathy, brain MRI abnormality; intellectual disability, childhood-onset optic atrophy, ataxia Review for gene: SNF8 was set to GREEN gene: SNF8 was marked as current diagnostic Added comment: PMID: 38423010 - Nine individuals from six families presenting with a spectrum of neurodevelopmental/neurodegenerative features caused by bi-allelic variants in SNF8. In total, three putative LoF variants and four missense variants were identified. - The phenotypic spectrum included four individuals with severe developmental and epileptic encephalopathy, massive reduction of white matter, hypo-/aplasia of the corpus callosum, neurodevelopmental arrest, and early death. A second cohort shows a milder phenotype with intellectual disability, childhood-onset optic atrophy, or ataxia. All mildly affected individuals shared the same hypomorphic variant, c.304G>A (p.Val102Ile) as compound heterozygous. - Functional studies using fibroblasts derived from patients and zebrafish model showed LoF is the disease mech. Sources: Literature |
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| Callosome v0.380 | NDUFAF4 |
Krithika Murali changed review comment from: Brain anomalies noted but not involving corpus callosum. PMID: 32949790 - report two siblings with facial dysmorphism and lactic acidosis diagnosed neonatally with subsequent fatal early encephalopathy with apneic episodes, irritability, central hypoventilation, liver involvement and hyperammonemia. Cerebral white matter anomalies reported in one patient and cardiomyopathy in the other. WES identified homozygous nonsense NDUFAF4 variants with absent NDUFAF4 expression in patient fibroblasts. OXPHOS assembly studies demonstrated almost undetectable levels of fully assembled complex I and complex I–containing supercomplexes and an abnormal accumulation of SCIII2IV1 supercomplexes. Morphologically, fibroblasts showed rounder mitochondria and a diminished degree of branching of the mitochondrial network. PMID: 28853723 - report one patient born at 38 weeks after IOL for IUGR. Presented age 7 months with developmental regression, growth failure and central hypotonia. Brain MRI revealed diffuse bilateral signal alterations in the basal ganglia and thalami and an EEG showed generalized slowing with multifocal spikes consistent with an epileptogenic focus. Homozygous missense NDUFAF4 variants identified. Lentiviral complementation of patient fibroblasts with wild-type NDUFAF4 rescued complex I deficiency and assembly defect; to: Brain anomalies noted but not involving corpus callosum. PMID: 32949790 - report two siblings with facial dysmorphism and lactic acidosis diagnosed neonatally with subsequent fatal early encephalopathy with apneic episodes, irritability, central hypoventilation, liver involvement and hyperammonemia. Cerebral white matter anomalies reported in one patient and cardiomyopathy in the other. WES identified homozygous nonsense NDUFAF4 variants with absent NDUFAF4 expression in patient fibroblasts. OXPHOS assembly studies demonstrated almost undetectable levels of fully assembled complex I and complex I–containing supercomplexes and an abnormal accumulation of SCIII2IV1 supercomplexes. Morphologically, fibroblasts showed rounder mitochondria and a diminished degree of branching of the mitochondrial network. PMID: 28853723 - report one patient born at 38 weeks after IOL for IUGR. Presented age 7 months with developmental regression, growth failure and central hypotonia. Brain MRI revealed diffuse bilateral signal alterations in the basal ganglia and thalami and an EEG showed generalized slowing with multifocal spikes consistent with an epileptogenic focus. Homozygous missense NDUFAF4 variants identified. Lentiviral complementation of patient fibroblasts with wild-type NDUFAF4 rescued complex I deficiency and assembly defect PMID 18179882 - report multiple affected individuals from one family. Most presented soon after birth with severe metabolic acidosis and high plasma lactate levels. Patients who survived longer were repeatedly admitted because of exacerbation of the acidosis during intercurrent infections. One long-term survivor had profound ID. Seizures occurred in 2 individuals during decompensation episodes. Brain MRI of one patient at 16 months of age revealed severe atrophy of both gray and white matter, with demyelination, most prominent at the anterior aspects of the brain, leaving a cortical ribbon. At the occipito-parietal region there were subventricular cysts, emphasizing the ventricular walls. The cerebellum, basal ganglia, pons, and medulla were severely atrophic |
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| Callosome v0.303 | HID1 |
Zornitza Stark gene: HID1 was added gene: HID1 was added to Callosome. Sources: Literature Mode of inheritance for gene: HID1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: HID1 were set to 33999436 Phenotypes for gene: HID1 were set to Syndromic infantile encephalopathy; Hypopituitarism Review for gene: HID1 was set to GREEN Added comment: 7 individuals from 6 unrelated families reported. Clinical features included: hypopituitarism in combination with brain atrophy, thin corpus callosum, severe developmental delay, visual impairment, and epilepsy Sources: Literature |
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| Callosome v0.219 | SHMT2 |
Zornitza Stark gene: SHMT2 was added gene: SHMT2 was added to Callosome. Sources: Literature Mode of inheritance for gene: SHMT2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SHMT2 were set to 33015733 Phenotypes for gene: SHMT2 were set to Congenital microcephaly; Infantile axial hypotonia; Spastic paraparesis; Global developmental delay; Intellectual disability; Abnormality of the corpus callosum; Abnormal cortical gyration; Hypertrophic cardiomyopathy; Abnormality of the face; Proximal placement of thumb; 2-3 toe syndactyly Review for gene: SHMT2 was set to GREEN Added comment: García‑Cazorla et al. (2020 - PMID: 33015733) report 5 individuals (from 4 families) with a novel brain and heart developmental syndrome caused by biallelic SHMT2 pathogenic variants. All affected subjects presented similar phenotype incl. microcephaly at birth (5/5 with OFC < -2 SD though in 2/5 cases N OFC was observed later), DD and ID (1/5 mild-moderate, 1/5 moderate, 3/5 severe), motor dysfunction in the form of spastic (5/5) paraparesis, ataxia/dysmetria (3/4), intention tremor (in 3/?) and/or peripheral neuropathy (2 sibs). They exhibited corpus callosum hypoplasia (5/5) and perisylvian microgyria-like pattern (4/5). Cardiac problems were reported in all, with hypertrophic cardiomyopathy in 4/5 (from 3 families) and atrial-SD in the 5th individual (1/5). Common dysmorphic features incl. long palpebral/fissures, eversion of lateral third of lower eylids, arched eyebrows, long eyelashes, thin upper lip, short Vth finger, fetal pads, mild 2-3 toe syndactyly, proximally placed thumbs. Biallelic variants were identified following exome sequencing in all (other investigations not mentioned). Identified variants were in all cases missense SNVs or in-frame del, which together with evidence from population databases and mouse model might suggest a hypomorphic effect of variants and intolerance/embryonic lethality for homozygous LoF ones. SHMT2 encodes the mitohondrial form of serine hydroxymethyltransferase. The enzyme transfers one-carbon units from serine to tetrahydrofolate (THF) and generates glycine and 5,10,methylene-THF. Mitochondrial defect was suggested by presence of ragged red fibers in myocardial biopsy of one patient. Quadriceps and myocardial biopsies of the same individual were overall suggestive of myopathic changes. While plasma metabolites were within N range and SHMT2 protein levels not significantly altered in patient fibroblasts, the authors provide evidence for impaired enzymatic function eg. presence of the SHMT2 substrate (THF) in patient but not control (mitochondria-enriched) fibroblasts , decrease in glycine/serine ratios, impared folate metabolism. Patient fibroblasts displayed impaired oxidative capacity (reduced ATP levels in a medium without glucose, diminished oxygen consumption rates). Mitochondrial membrane potential and ROS levels were also suggestive of redox malfunction. Shmt2 ko in mice was previously shown to be embryonically lethal attributed to severe mitochondrial respiration defects, although there was no observed brain metabolic defect. The authors performed Shmt2 knockdown in motoneurons in Drosophila, demonstrating neuromuscular junction (# of satellite boutons) and motility defects (climbing distance/velocity). Sources: Literature |
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| Callosome v0.215 | NR2F1 | Zornitza Stark Phenotypes for gene: NR2F1 were changed from to Bosch-Boonstra-Schaaf optic atrophy syndrome, MIM# 615722 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Callosome v0.211 | NR2F1 | Zornitza Stark reviewed gene: NR2F1: Rating: RED; Mode of pathogenicity: None; Publications: 32275123; Phenotypes: Bosch-Boonstra-Schaaf optic atrophy syndrome, MIM# 615722; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Callosome v0.0 | ATRX |
Zornitza Stark gene: ATRX was added gene: ATRX was added to Corpus callosum agenesis, Callosome_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services Mode of inheritance for gene: ATRX was set to Unknown |
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| Callosome v0.0 | ATR |
Zornitza Stark gene: ATR was added gene: ATR was added to Corpus callosum agenesis, Callosome_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services Mode of inheritance for gene: ATR was set to Unknown |
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