rs794727228
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PP3_StrongPP5
The NM_013382.7(POMT2):c.1958C>T(p.Pro653Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,402 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. P653P) has been classified as Likely benign.
Frequency
Consequence
NM_013382.7 missense
Scores
Clinical Significance
Conservation
Publications
- muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A2Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- myopathy caused by variation in POMT2Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B2Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
- autosomal recessive limb-girdle muscular dystrophy type 2NInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- congenital muscular dystrophy with cerebellar involvementInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- congenital muscular dystrophy with intellectual disabilityInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- muscle-eye-brain diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- muscular dystrophy-dystroglycanopathy, type AInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251282 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000821 AC: 12AN: 1461402Hom.: 0 Cov.: 30 AF XY: 0.00000688 AC XY: 5AN XY: 727046 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
not provided Uncertain:3
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Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A2;C3150416:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B2;C3150418:Autosomal recessive limb-girdle muscular dystrophy type 2N Pathogenic:2
In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 194966). This missense change has been observed in individual(s) with clinical features of POMT2-related conditions (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs794727228, gnomAD 0.006%). This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 653 of the POMT2 protein (p.Pro653Leu). -
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Autosomal recessive limb-girdle muscular dystrophy Pathogenic:1
Variant summary: POMT2 c.1958C>T (p.Pro653Leu) results in a non-conservative amino acid change located in the Protein O-mannosyl-transferase, C-terminal four TM domain (IPR032421) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 4e-06 in 251282 control chromosomes. c.1958C>T has been observed in the homozygous and presumed compound heterozygous state in at least 3 individual(s) affected with autosomal recessive Limb-Girdle Muscular Dystrophy, Autosomal Recessive (Labcorp Genetics (formerlyInvitae)), including at least 1 family where it segregated with disease. These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. ClinVar contains an entry for this variant (Variation ID: 194966). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A2 Uncertain:1
The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Predicted Consequence/Location: The majority of the known disease-causing variants of this gene are variants expected to result in premature termination of the protein. In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.94 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.86 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change has been previously reported to be associated with POMT2 related disorder (ClinVar ID: VCV000194966). However, the evidence of pathogenicity is insufficient at this time. Therefore, this variant is classified as VUS according to the recommendation of ACMG/AMP guideline. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at