rs202202445

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PVS1_Moderate

The NM_001077365.2(POMT1):​c.2167C>T​(p.Arg723*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000441 in 1,611,020 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000045 ( 0 hom. )

Consequence

POMT1
NM_001077365.2 stop_gained

Scores

3
3
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 2.38

Publications

7 publications found
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]
POMT1 Gene-Disease associations (from GenCC):
  • muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Ambry Genetics, Laboratory for Molecular Medicine, Genomics England PanelApp
  • myopathy caused by variation in POMT1
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1
    Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • autosomal recessive limb-girdle muscular dystrophy type 2K
    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
  • congenital muscular dystrophy without 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: Uncertain_significance. The variant received 2 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.00505 CDS is truncated, and there are 0 pathogenic variants in the truncated region.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POMT1NM_001077365.2 linkc.2167C>T p.Arg723* stop_gained Exon 20 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.2167C>T p.Arg723* stop_gained Exon 20 of 20 1 NM_001077365.2 ENSP00000385797.4 Q9Y6A1-2

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152186
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.000288
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000924
AC:
23
AN:
248830
AF XY:
0.0000966
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000523
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000885
Gnomad OTH exome
AF:
0.000492
GnomAD4 exome
AF:
0.0000446
AC:
65
AN:
1458716
Hom.:
0
Cov.:
34
AF XY:
0.0000413
AC XY:
30
AN XY:
725578
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33410
American (AMR)
AF:
0.000448
AC:
20
AN:
44636
Ashkenazi Jewish (ASJ)
AF:
0.0000767
AC:
2
AN:
26082
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85978
European-Finnish (FIN)
AF:
0.0000191
AC:
1
AN:
52472
Middle Eastern (MID)
AF:
0.000223
AC:
1
AN:
4484
European-Non Finnish (NFE)
AF:
0.0000333
AC:
37
AN:
1111716
Other (OTH)
AF:
0.0000498
AC:
3
AN:
60240
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
5
10
14
19
24
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
AF:
0.0000394
AC:
6
AN:
152304
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74466
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41570
American (AMR)
AF:
0.0000654
AC:
1
AN:
15302
Ashkenazi Jewish (ASJ)
AF:
0.000288
AC:
1
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000591
Hom.:
0
Bravo
AF:
0.0000378
ExAC
AF:
0.0000494
AC:
6
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Feb 01, 2021
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 31, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Feb 12, 2015
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Dec 03, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not expected to trigger nonsense-mediated mRNA decay Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Autosomal recessive limb-girdle muscular dystrophy type 2K;C4284790:Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1;C5436962:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1 Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Walker-Warburg congenital muscular dystrophy;C1836373:Autosomal recessive limb-girdle muscular dystrophy type 2K;C5436962:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1 Uncertain:1
Nov 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg745*) in the POMT1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 3 amino acid(s) of the POMT1 protein. This variant is present in population databases (rs202202445, gnomAD 0.05%). This variant has not been reported in the literature in individuals affected with POMT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 211946). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.28
D
BayesDel_noAF
Pathogenic
0.50
CADD
Pathogenic
45
DANN
Uncertain
1.0
Eigen
Pathogenic
0.72
Eigen_PC
Uncertain
0.57
FATHMM_MKL
Uncertain
0.95
D
PhyloP100
2.4
Vest4
0.46
GERP RS
4.0
Mutation Taster
=34/166
disease causing

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: rs202202445; hg19: chr9-134398482; API