Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_017739.4(POMGNT1):c.931C>T(p.Arg311*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,006 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
POMGNT1 (HGNC:19139): (protein O-linked mannose N-acetylglucosaminyltransferase 1 (beta 1,2-)) This gene encodes a type II transmembrane protein that resides in the Golgi apparatus. It participates in O-mannosyl glycosylation and is specific for alpha linked terminal mannose. Mutations in this gene may be associated with muscle-eye-brain disease and several congenital muscular dystrophies. Alternatively spliced transcript variants that encode different protein isoforms have been described. [provided by RefSeq, Feb 2014]
TSPAN1 (HGNC:20657): (tetraspanin 1) The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains. The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. [provided by RefSeq, Jul 2008]
Verdict is Pathogenic. Variant got 18 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-46193874-G-A is Pathogenic according to our data. Variant chr1-46193874-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 56610.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-46193874-G-A is described in Lovd as [Likely_pathogenic]. Variant chr1-46193874-G-A is described in Lovd as [Pathogenic]. Variant chr1-46193874-G-A is described in Lovd as [Pathogenic].
The R311X variant in the POMGNT1 gene has been reported previously in two unrelated individuals with muscle eye brain disease, both of whom harbored a second POMGNT1 variant (Biancheri et al., 2006; Saredi et al., 2012). This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The R311X variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). We interpret R311X as a pathogenic variant. -
Pathogenic, criteria provided, single submitter
clinical testing
Eurofins Ntd Llc (ga)
Jun 11, 2013
- -
Pathogenic, criteria provided, single submitter
clinical testing
Athena Diagnostics
Nov 27, 2018
The variant creates a premature nonsense codon, and is therefore predicted to result in the loss of a functional protein. Found in at least one symptomatic patient, and not found in general population data. -
Muscle eye brain disease Pathogenic:3
Likely pathogenic, no assertion criteria provided
clinical testing
Counsyl
Apr 02, 2015
- -
Likely pathogenic, no assertion criteria provided
literature only
Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)
-
- -
Pathogenic, no assertion criteria provided
clinical testing
Natera, Inc.
Sep 16, 2020
- -
Retinitis pigmentosa 76 Pathogenic:1
Likely pathogenic, no assertion criteria provided
clinical testing
Counsyl
Apr 02, 2015
- -
Autosomal recessive limb-girdle muscular dystrophy type 2O Pathogenic:1
Likely pathogenic, no assertion criteria provided
clinical testing
Counsyl
Apr 02, 2015
- -
Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O;C3151519:Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A3;C4310704:Retinitis pigmentosa 76 Pathogenic:1
Pathogenic, criteria provided, single submitter
clinical testing
Fulgent Genetics, Fulgent Genetics
May 17, 2024
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Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O Pathogenic:1
Pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Dec 14, 2023
This sequence change creates a premature translational stop signal (p.Arg311*) in the POMGNT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in POMGNT1 are known to be pathogenic (PMID: 19299310, 20816175, 21447391, 26908613, 27391550). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with muscular dystrophy-dystroglycanopathy (PMID: 17030669, 22554691). ClinVar contains an entry for this variant (Variation ID: 56610). For these reasons, this variant has been classified as Pathogenic. -
Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3 Pathogenic:1
Likely pathogenic, no assertion criteria provided
clinical testing
Counsyl
Apr 02, 2015
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Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A3 Pathogenic:1