NM_001077365.2:c.1939G>A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2PP3_ModeratePP5_Very_Strong

The NM_001077365.2(POMT1):​c.1939G>A​(p.Ala647Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,972 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

POMT1
NM_001077365.2 missense

Scores

12
6
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 9.53
Variant links:
Genes affected
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.911
PP5
Variant 9-131522160-G-A is Pathogenic according to our data. Variant chr9-131522160-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3250.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-131522160-G-A is described in Lovd as [Pathogenic]. Variant chr9-131522160-G-A is described in Lovd as [Benign]. Variant chr9-131522160-G-A is described in Lovd as [Likely_pathogenic]. Variant chr9-131522160-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POMT1NM_001077365.2 linkc.1939G>A p.Ala647Thr missense_variant Exon 19 of 20 ENST00000402686.8 NP_001070833.1 Q9Y6A1-2A0A140VKE0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POMT1ENST00000402686.8 linkc.1939G>A p.Ala647Thr missense_variant Exon 19 of 20 1 NM_001077365.2 ENSP00000385797.4 Q9Y6A1-2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152150
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461822
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727218
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000270
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152150
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74328
show subpopulations
Gnomad4 AFR
AF:
0.0000483
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000236
Hom.:
0
Bravo
AF:
0.0000264
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:4
Jul 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

POMT1: PM3:Strong, PM2 -

May 30, 2024
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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; This variant is associated with the following publications: (PMID: 18513969, 17869517, 22549409, 16717220, 24491487, 31589614, 30838351, 33963534, 19299310, 31066050, 17878207, 29419866, 34602496, 31031587, 34565739, 30454682, 35948506) -

Jul 13, 2018
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 14, 2017
Athena Diagnostics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1 Pathogenic:2
Jan 23, 2024
Baylor Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Oct 20, 2023
3billion
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. 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. Premature termination of the protein is a common disease-causing mechanism for this gene. In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.93 (>=0.6, sensitivity 0.68 and specificity 0.92)]. Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000003250 /PMID: 16717220). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -

Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1 Pathogenic:1
Dec 01, 2012
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

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
Feb 17, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 669 of the POMT1 protein (p.Ala669Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with ongenital muscular dystrophy and limb girdle muscular dystrophy (PMID: 16717220, 17869517, 17878207, 20816175; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 3250). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on POMT1 protein function. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.68
BayesDel_addAF
Pathogenic
0.53
D
BayesDel_noAF
Pathogenic
0.52
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.96
.;.;.;D;.;D
Eigen
Pathogenic
0.83
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.95
D;D;D;D;.;D
M_CAP
Pathogenic
0.52
D
MetaRNN
Pathogenic
0.91
D;D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.4
.;.;.;M;.;.
PrimateAI
Uncertain
0.58
T
PROVEAN
Uncertain
-3.4
D;D;D;D;D;D
REVEL
Pathogenic
0.93
Sift
Uncertain
0.0020
D;D;D;D;D;D
Sift4G
Uncertain
0.0040
D;D;D;D;D;D
Polyphen
1.0
.;D;.;D;D;.
Vest4
0.92
MVP
0.97
MPC
0.59
ClinPred
0.97
D
GERP RS
5.5
Varity_R
0.82
gMVP
0.77

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs119462987; hg19: chr9-134397547; COSMIC: COSV61225439; COSMIC: COSV61225439; API