Our verdict is Likely pathogenic. Variant got 9 ACMG points: 10P and 1B. PVS1PM2BP6
The NM_001374689.1(POMT1):c.904G>T(p.Glu302*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000204 in 1,614,046 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Variant results in nonsense mediated mRNA decay.
POMT1 (HGNC:9202): (protein O-mannosyltransferase 1) The protein encoded by this gene is an O-mannosyltransferase that requires interaction with the product of the POMT2 gene for enzymatic function. The encoded protein is found in the membrane of the endoplasmic reticulum. Defects in this gene are a cause of Walker-Warburg syndrome (WWS) and limb-girdle muscular dystrophy type 2K (LGMD2K). Several transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Oct 2008]
Verdict is Likely_pathogenic. Variant got 9 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;
BP6
Variant 9-131511402-G-T is Benign according to our data. Variant chr9-131511402-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 436379.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.
Genetic Services Laboratory, University of Chicago
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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not provided Uncertain:1
Sep 14, 2017
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Walker-Warburg congenital muscular dystrophy;C1836373:Autosomal recessive limb-girdle muscular dystrophy type 2K;C5436962:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1 Benign:1
Jan 06, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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POMT1-related disorder Benign:1
Aug 28, 2024
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -