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

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

POMT2
NM_013382.7 missense

Scores

15
3
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:4

Conservation

PhyloP100: 9.84

Publications

2 publications found
Variant links:
Genes affected
POMT2 (HGNC:19743): (protein O-mannosyltransferase 2) The protein encoded by this gene is an O-mannosyltransferase that requires interaction with the product of the POMT1 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).[provided by RefSeq, Oct 2008]
POMT2 Gene-Disease associations (from GenCC):
  • muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A2
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • myopathy caused by variation in POMT2
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B2
    Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
  • autosomal recessive limb-girdle muscular dystrophy type 2N
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • congenital muscular dystrophy with cerebellar involvement
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • congenital muscular dystrophy with intellectual disability
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • muscle-eye-brain disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • muscular dystrophy-dystroglycanopathy, type A
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_013382.7
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.963
PP5
Variant 14-77278803-G-A is Pathogenic according to our data. Variant chr14-77278803-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 194966.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POMT2NM_013382.7 linkc.1958C>T p.Pro653Leu missense_variant Exon 19 of 21 ENST00000261534.9 NP_037514.2 Q9UKY4-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POMT2ENST00000261534.9 linkc.1958C>T p.Pro653Leu missense_variant Exon 19 of 21 1 NM_013382.7 ENSP00000261534.4 Q9UKY4-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251282
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461402
Hom.:
0
Cov.:
30
AF XY:
0.00000688
AC XY:
5
AN XY:
727046
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53220
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00000720
AC:
8
AN:
1111764
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:3Uncertain:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
May 01, 2018
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 21, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 30, 2022
GeneDx
Significance:Uncertain significance
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; 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
Jun 27, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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). -

Apr 17, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy Pathogenic:1
Jun 20, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Feb 27, 2024
3billion
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.79
BayesDel_addAF
Pathogenic
0.48
D
BayesDel_noAF
Pathogenic
0.62
CADD
Pathogenic
32
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.94
D
Eigen
Pathogenic
0.73
Eigen_PC
Pathogenic
0.75
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Pathogenic
0.40
D
MetaRNN
Pathogenic
0.96
D
MetaSVM
Uncertain
0.40
D
MutationAssessor
Pathogenic
4.2
H
PhyloP100
9.8
PrimateAI
Uncertain
0.70
T
PROVEAN
Pathogenic
-8.5
D
REVEL
Pathogenic
0.94
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.97
MutPred
0.78
Gain of catalytic residue at Y651 (P = 0.0037);
MVP
0.98
MPC
0.46
ClinPred
1.0
D
GERP RS
5.8
Varity_R
0.95
gMVP
0.93
Mutation Taster
=18/82
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs794727228; hg19: chr14-77745146; COSMIC: COSV105055031; COSMIC: COSV105055031; API