Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2PP3_StrongPP5_Moderate
The NM_001411024.1(POMT1):c.-579G>A variant causes a 5 prime UTR premature start codon gain change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).
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 8 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
PP3
BayesDel_addAF computational evidence supports a deleterious effect, 0.625
PP5
Variant 9-131509761-G-A is Pathogenic according to our data. Variant chr9-131509761-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 212739.Status of the report is criteria_provided_single_submitter, 1 stars.
Walker-Warburg congenital muscular dystrophy;C1836373:Autosomal recessive limb-girdle muscular dystrophy type 2K;C5436962:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1 Pathogenic:1
May 09, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 212739). This variant has not been reported in the literature in individuals affected with POMT1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Trp186*) in the POMT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in POMT1 are known to be pathogenic (PMID: 12369018, 15637732, 16575835). -
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1 Pathogenic:1
Jul 29, 2014
Knight Diagnostic Laboratories, Oregon Health and Sciences University