rs138745073

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP3_ModeratePP5

The NM_017739.4(POMGNT1):​c.1010T>C​(p.Ile337Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000446 in 1,614,084 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I337V) has been classified as Uncertain significance.

Frequency

Genomes: š‘“ 0.0000066 ( 0 hom., cov: 33)
Exomes š‘“: 0.000049 ( 0 hom. )

Consequence

POMGNT1
NM_017739.4 missense

Scores

10
8
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:7

Conservation

PhyloP100: 8.34

Publications

3 publications found
Variant links:
Genes affected
POMGNT1 (HGNC:19139): (protein O-linked mannose N-acetylglucosaminyltransferase 1 (beta 1,2-)) This gene encodes a type II transmembrane protein that resides in the Golgi apparatus. It participates in O-mannosyl glycosylation and is specific for alpha linked terminal mannose. Mutations in this gene may be associated with muscle-eye-brain disease and several congenital muscular dystrophies. Alternatively spliced transcript variants that encode different protein isoforms have been described. [provided by RefSeq, Feb 2014]
TSPAN1 (HGNC:20657): (tetraspanin 1) The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains. The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.914
PP5
Variant 1-46193580-A-G is Pathogenic according to our data. Variant chr1-46193580-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 285192.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POMGNT1NM_017739.4 linkc.1010T>C p.Ile337Thr missense_variant Exon 11 of 22 ENST00000371984.8 NP_060209.4 Q8WZA1-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POMGNT1ENST00000371984.8 linkc.1010T>C p.Ile337Thr missense_variant Exon 11 of 22 1 NM_017739.4 ENSP00000361052.3 Q8WZA1-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251316
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.000145
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000486
AC:
71
AN:
1461880
Hom.:
0
Cov.:
90
AF XY:
0.0000523
AC XY:
38
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000134
AC:
6
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000522
AC:
58
AN:
1112008
Other (OTH)
AF:
0.0000993
AC:
6
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
6
12
18
24
30
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74356
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000564
Hom.:
0
Bravo
AF:
0.0000264
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:7
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:3
Sep 13, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 22, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 05, 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; This variant is associated with the following publications: (PMID: 24282183, 30564623) -

Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O;C3151519:Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A3;C4310704:Retinitis pigmentosa 76 Pathogenic:1
Jun 02, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O Pathogenic:1
Dec 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 337 of the POMGNT1 protein (p.Ile337Thr). This variant is present in population databases (rs138745073, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of retinitis pigmentosa (internal data). 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. ClinVar contains an entry for this variant (Variation ID: 285192). Invitae Evidence 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 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 POMGNT1 protein function. 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. -

Inborn genetic diseases Uncertain:1
Apr 21, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1010T>C (p.I337T) alteration is located in exon 11 (coding exon 10) of the POMGNT1 gene. This alteration results from a T to C substitution at nucleotide position 1010, causing the isoleucine (I) at amino acid position 337 to be replaced by a threonine (T). The p.I337T alteration is predicted to be deleterious by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Muscular dystrophy-dystroglycanopathy Uncertain:1
Apr 29, 2025
Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:curation

The p.Ile337Thr variant in POMGNT1 has not been previously reported in the literature in individuals with muscular dystrophy-dystroglycanopathy, but has been identified in 0.01% (6/60000) of Admixed American chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs138745073). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (VCV000285192.16) as likely pathogenic by Labcorp Genetics, and as a variant of uncertain significance by Eurofins Ntd Llc, Fulgent Genetics, GeneDx, Revvity Omics, Dept Of Ophthalmology (Nagoya University), and Ambry Genetics. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of the p.Ile337Thr variant is uncertain. ACMG/AMP Criteria applied: PM2_Supporting, PP3_moderate (Richards 2015). -

Retinal dystrophy Uncertain:1
Oct 01, 2023
Dept Of Ophthalmology, Nagoya University
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Muscle eye brain disease;C3150412:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O;C4310704:Retinitis pigmentosa 76 Uncertain:1
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.84
BayesDel_addAF
Pathogenic
0.24
D
BayesDel_noAF
Pathogenic
0.36
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.95
D;.
Eigen
Pathogenic
0.77
Eigen_PC
Pathogenic
0.72
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.97
D;D
M_CAP
Uncertain
0.29
D
MetaRNN
Pathogenic
0.91
D;D
MetaSVM
Uncertain
0.48
D
MutationAssessor
Uncertain
2.1
M;M
PhyloP100
8.3
PrimateAI
Pathogenic
0.88
D
PROVEAN
Uncertain
-3.9
D;D
REVEL
Pathogenic
0.88
Sift
Uncertain
0.0010
D;D
Sift4G
Uncertain
0.0030
D;D
Polyphen
1.0
D;.
Vest4
0.98
MVP
0.95
MPC
1.0
ClinPred
0.83
D
GERP RS
5.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.96
gMVP
0.77
Mutation Taster
=18/82
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs138745073; hg19: chr1-46659252; API