Browse
Submit Data
Databases
API
Help

Dataset Information

23 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Exome sequencing identifies novel missense and deletion variants in RTN4IP1 associated with optic atrophy, global developmental delay, epilepsy, ataxia, and choreoathetosis.

ABSTRACT: Inherited optic neuropathies (IONs) are neurodegenerative disorders characterized by optic atrophy with or without extraocular manifestations. Optic atrophy-10 (OPA10) is an autosomal recessive ION recently reported to be caused by mutations in RTN4IP1, which encodes reticulon 4 interacting protein 1 (RTN4IP1), a mitochondrial ubiquinol oxydo-reductase. Here we report novel compound heterozygous mutations in RTN4IP1 in a male proband with developmental delay, epilepsy, optic atrophy, ataxia, and choreoathetosis. Workup was notable for transiently elevated lactate and lactate-to-pyruvate ratio, brain magnetic resonance imaging with optic atrophy and T2 signal abnormalities, and a nondiagnostic initial genetic workup, including chromosomal microarray and mitochondrial panel testing. Exome sequencing identified a paternally inherited missense variant (c.263T>G, p.Val88Gly) predicted to be deleterious and a maternally inherited deletion encompassing RTN4IP1. To our knowledge, this is the first report of a non-single nucleotide pathogenic variant associated with OPA10. This case highlights the expanding phenotypic spectrum of OPA10, the association between "syndromic" cases and severe RTN4IP1 mutations, and the importance of nonbiased genetic testing, such as ES, to analyze multiple genes and variants types, in patients suspected of having genetic disease.

SUBMITTER: D'Gama AM

PROVIDER: S-EPMC8388561 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Biallelic in-frame deletion in TRAPPC4 in a family with developmental delay and cerebellar atrophy.

Project description: Not available

| S-EPMC7586085 | biostudies-literature

Mutations in GPAA1, Encoding a GPI Transamidase Complex Protein, Cause Developmental Delay, Epilepsy, Cerebellar Atrophy, and Osteopenia.

Project description:Approximately one in every 200 mammalian proteins is anchored to the cell membrane through a glycosylphosphatidylinositol (GPI) anchor. These proteins play important roles notably in neurological development and function. To date, more than 20 genes have been implicated in the biogenesis of GPI-anchored proteins. GPAA1 (glycosylphosphatidylinositol anchor attachment 1) is an essential component of the transamidase complex along with PIGK, PIGS, PIGT, and PIGU (phosphatidylinositol-glycan biosynthesis classes K, S, T, and U, respectively). This complex orchestrates the attachment of the GPI anchor to the C terminus of precursor proteins in the endoplasmic reticulum. Here, we report bi-allelic mutations in GPAA1 in ten individuals from five families. Using whole-exome sequencing, we identified two frameshift mutations (c.981_993del [p.Gln327Hisfs?102] and c.920delG [p.Gly307Alafs?11]), one intronic splicing mutation (c.1164+5C>T), and six missense mutations (c.152C>T [p.Ser51Leu], c.160_161delinsAA [p.Ala54Asn], c.527G>C [p.Trp176Ser], c.869T>C [p.Leu290Pro], c.872T>C [p.Leu291Pro], and c.1165G>C [p.Ala389Pro]). Most individuals presented with global developmental delay, hypotonia, early-onset seizures, cerebellar atrophy, and osteopenia. The splicing mutation was found to decrease GPAA1 mRNA. Moreover, flow-cytometry analysis of five available individual samples showed that several GPI-anchored proteins had decreased cell-surface abundance in leukocytes (FLAER, CD16, and CD59) or fibroblasts (CD73 and CD109). Transduction of fibroblasts with a lentivirus encoding the wild-type protein partially rescued the deficiency of GPI-anchored proteins. These findings highlight the role of the transamidase complex in the development and function of the cerebellum and the skeletal system.

| S-EPMC5673666 | biostudies-literature

Exome sequencing study of partial agenesis of the corpus callosum in men with developmental delay, epilepsy, and microcephaly.

Project description:BACKGROUND:This study reports the genetic features of four Caucasian males from the Saguenay-Lac-St-Jean region affected by partial agenesis of the corpus callosum (ACC) with hypotonia, epilepsy, developmental delay, microcephaly, hypoplasia, and autistic behavior. METHODS:We performed whole exome sequencing (WES) to identify new genes involved in this pathological phenotype. The regions of interest were subsequently sequenced for family members. RESULTS:Single-nucleotide variations (SNVs) and insertions or deletions were detected in genes potentially implicated in brain defects observed in these patients. One patient did not have mutations in genes related to ACC, but carried a de novo pathogenic mutation in Mucolipin-1 (MCOLN1) and was diagnosed with mucolipidosis type IV. Among the other probands, missense SNVs were observed in DCLK2 (Doublecortin Like Kinase 2), HERC2 (HECT And RLD Domain Containing E3 Ubiquitin Protein Ligase 2), and KCNH3 (Potassium channel, voltage-gated, subfamily H, member 3). One patient also carried a non-frameshift insertion in CACNA1A (Cav2.1(P/Q-type) calcium channels). CONCLUSION:Although no common genetic defect was observed in this study, we provide evidence for new avenues of investigation for ACC, such as molecular pathways involving HERC2, CACNA1A, KCNH3, and more importantly DCLK2. We also allowed to diagnose an individual with mucolipidosis type IV.

| S-EPMC6978259 | biostudies-literature

SLC6A1 G443D associated with developmental delay and epilepsy.

Project description:SLC6A1 is associated with an autosomal dominant early-onset seizure and epileptic encephalopathy associated with intellectual disability. We present a 2-yr-old girl with developmental delay and epilepsy, using a new computational filtering impact score to show the patient's variant ranks with other pathogenic variants. Genomic studies within the patient revealed a G443D variant of uncertain significance. Structural and evolutionary assessments establish this variant as a loss of function to the protein. Compiled metrics through our custom tools on sequence, structure, and protein dynamics combined with PolyPhen-2, PROVEAN, SIFT, and Align-GVGD reveal this variant to rank in the top functional outcome changes relative to gnomAD, TOPMed, and ClinVar variants known to date. The patient was resistant to multiple epileptic drugs, finally finding that valproic acid controls the seizures. This is consistent with additional groups studying SLC6A1 variants within patients.

| S-EPMC7476406 | biostudies-literature

Macrocephaly and developmental delay caused by missense variants in RAB5C.

Project description:Rab GTPases are important regulators of intracellular vesicular trafficking. RAB5C is a member of the Rab GTPase family that plays an important role in the endocytic pathway, membrane protein recycling and signaling. Here we report on 12 individuals with nine different heterozygous de novo variants in RAB5C. All but one patient with missense variants (n = 9) exhibited macrocephaly, combined with mild-to-moderate developmental delay. Patients with loss of function variants (n = 2) had an apparently more severe clinical phenotype with refractory epilepsy and intellectual disability but a normal head circumference. Four missense variants were investigated experimentally. In vitro biochemical studies revealed that all four variants were damaging, resulting in increased nucleotide exchange rate, attenuated responsivity to guanine exchange factors and heterogeneous effects on interactions with effector proteins. Studies in C. elegans confirmed that all four variants were damaging in vivo and showed defects in endocytic pathway function. The variant heterozygotes displayed phenotypes that were not observed in null heterozygotes, with two shown to be through a dominant negative mechanism. Expression of the human RAB5C variants in zebrafish embryos resulted in defective development, further underscoring the damaging effects of the RAB5C variants. Our combined bioinformatic, in vitro and in vivo experimental studies and clinical data support the association of RAB5C missense variants with a neurodevelopmental disorder characterized by macrocephaly and mild-to-moderate developmental delay through disruption of the endocytic pathway.

| S-EPMC10586195 | biostudies-literature

Novel Missense <i>CNTNAP2</i> Variant Identified in Two Consanguineous Pakistani Families With Developmental Delay, Epilepsy, Intellectual Disability, and Aggressive Behavior.

Project description:We report the genetic analysis of two consanguineous pedigrees of Pakistani ancestry in which two siblings in each family exhibited developmental delay, epilepsy, intellectual disability and aggressive behavior. Whole-genome sequencing was performed in Family 1, and we identified ~80,000 variants located in regions of homozygosity. Of these, 615 variants had a minor allele frequency ≤ 0.001, and 21 variants had CADD scores ≥ 15. Four homozygous exonic variants were identified in both affected siblings: PDZD7 (c.1348_1350delGAG, p.Glu450del), ALG6 (c.1033G>C, p.Glu345Gln), RBM20 (c.1587C>G, p.Ser529Arg), and CNTNAP2 (c.785G>A, p.Gly228Arg). Sanger sequencing revealed co-segregation of the PDZD7, RBM20, and CNTNAP2 variants with disease in Family 1. Pathogenic variants in PDZD7 and RBM20 are associated with autosomal recessive non-syndromic hearing loss and autosomal dominant dilated cardiomyopathy, respectively, suggesting that these variants are unlikely likely to contribute to the clinical presentation. Gene panel analysis was performed on the two affected siblings in Family 2, and they were found to also be homozygous for the p.Gly228Arg CNTNAP2 variant. Together these families provide a LOD score 2.9 toward p.Gly228Arg CNTNAP2 being a completely penetrant recessive cause of this disease. The clinical presentation of the affected siblings in both families is also consistent with previous reports from individuals with homozygous CNTNAP2 variants where at least one allele was a nonsense variant, frameshift or small deletion. Our data suggests that homozygous CNTNAP2 missense variants can also contribute to disease, thereby expanding the genetic landscape of CNTNAP2 dysfunction.

| S-EPMC9329621 | biostudies-literature

Interstitial 12p deletion involving more than 40 genes in a patient with postnatal microcephaly, psychomotor delay, optic nerve atrophy, and facial dysmorphism.

Project description:Interstitial deletions of chromosome 12p are rare, and the phenotype spectrum is therefore still unknown. The thirteen patients reported so far suffer from developmental delay, optic nerve hypoplasia, micropenis, hypoplastic hair and skin, oligodontia, brachydactyly, and arterial hypertension. We report a de novo 12p12.2-p11.22 deletion of 9.2 Mb detected by array CGH analysis in a boy with global developmental delay, muscular hypotonia, postnatal microcephaly, facial dysmorphism including small ears, epicanthus, broad nasal bridge and hypoplastic nostrils. In addition, the patient had optic nerve atrophy, inverted nipples, micropenis, and a hemangioma. The deleted region encompasses more than 40 reference genes. We compare phenotype and deletion extent of our index patient to that of previous reports and thereby contribute to the understanding of interstitial 12p deletion phenotypes. Knowledge of the pattern of this deletion phenotype will help clinicians to diagnose this abnormality in their patients and to counsel the parents accordingly. Further descriptions may be able to contribute to the clarification.

| S-EPMC4287802 | biostudies-literature

Mitochondrial EFTs defects in juvenile-onset Leigh disease, ataxia, neuropathy, and optic atrophy.

Project description:ObjectiveWe report novel defects of mitochondrial translation elongation factor Ts (EFTs), with high carrier frequency in Finland and expand the manifestations of this disease group from infantile cardiomyopathy to juvenile neuropathy/encephalopathy disorders.MethodsDNA analysis, whole-exome analysis, protein biochemistry, and protein modeling.ResultsWe used whole-exome sequencing to find the genetic cause of infantile-onset mitochondrial cardiomyopathy, progressing to juvenile-onset Leigh syndrome, neuropathy, and optic atrophy in 2 siblings. We found novel compound heterozygous mutations, c.944G>A [p.C315Y] and c.856C>T [p.Q286X], in the TSFM gene encoding mitochondrial EFTs. The same p.Q286X variant was found as compound heterozygous with a splice site change in a patient from a second family, with juvenile-onset optic atrophy, peripheral neuropathy, and ataxia. Our molecular modeling predicted the coding-region mutations to cause protein instability, which was experimentally confirmed in cultured patient cells, with mitochondrial translation defect and lacking EFTs. Only a single TSFM mutation has been previously described in different populations, leading to an infantile fatal multisystem disorder with cardiomyopathy. Sequence data from 35,000 Finnish population controls indicated that the heterozygous carrier frequency of p.Q286X change was exceptionally high in Finland, 1:80, but no homozygotes were found in the population, in our mitochondrial disease patient collection, or in an intrauterine fetal death material, suggesting early developmental lethality of the homozygotes.ConclusionsWe show that in addition to early-onset cardiomyopathy, TSFM mutations should be considered in childhood and juvenile encephalopathies with optic and/or peripheral neuropathy, ataxia, or Leigh disease.

| S-EPMC4150129 | biostudies-literature

Utility of whole exome sequencing for the early diagnosis of pediatric-onset cerebellar atrophy associated with developmental delay in an inbred population.

Project description:BackgroundCerebellar atrophy and developmental delay are commonly associated features in large numbers of genetic diseases that frequently also include epilepsy. These defects are highly heterogeneous on both the genetic and clinical levels. Patients with these signs also typically present with non-specific neuroimaging results that can help prioritize further investigation but don't suggest a specific molecular diagnosis.MethodsTo genetically explore a cohort of 18 Egyptian families with undiagnosed cerebellar atrophy identified on MRI, we sequenced probands and some non-affected family members via high-coverage whole exome sequencing (WES; >97 % of the exome covered at least by 30x). Patients were mostly from consanguineous families, either sporadic or multiplex. We analyzed WES data and filtered variants according to dominant and recessive inheritance models.ResultsWe successfully identified disease-causing mutations in half of the families screened (9/18). These mutations are located in seven different genes, PLA2G6 being the gene most frequently mutated (n = 3). We also identified a recurrent de novo mutation in the KIF1A gene and a molybdenum cofactor deficiency caused by the loss of the start codon in the MOCS2A open-reading frame in a mildly affected subject.ConclusionsThis study illustrates the necessity of screening for dominant mutations in WES data from consanguineous families. Our identification of a patient with a mild and improving phenotype carrying a previously characterized severe loss of function mutation also broadens the clinical spectrum associated with molybdenum cofactor deficiency.

| S-EPMC4855324 | biostudies-literature

Mutation in ATG5 reduces autophagy and leads to ataxia with developmental delay.

Project description:Autophagy is required for the homeostasis of cellular material and is proposed to be involved in many aspects of health. Defects in the autophagy pathway have been observed in neurodegenerative disorders; however, no genetically-inherited pathogenic mutations in any of the core autophagy-related (ATG) genes have been reported in human patients to date. We identified a homozygous missense mutation, changing a conserved amino acid, in ATG5 in two siblings with congenital ataxia, mental retardation, and developmental delay. The subjects' cells display a decrease in autophagy flux and defects in conjugation of ATG12 to ATG5. The homologous mutation in yeast demonstrates a 30-50% reduction of induced autophagy. Flies in which Atg5 is substituted with the mutant human ATG5 exhibit severe movement disorder, in contrast to flies expressing the wild-type human protein. Our results demonstrate the critical role of autophagy in preventing neurological diseases and maintaining neuronal health.

| S-EPMC4786408 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data