rs375431575

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PP3_ModeratePP5

The NM_017739.4(POMGNT1):​c.385C>T​(p.Arg129Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000136 in 1,613,836 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. R129Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

POMGNT1
NM_017739.4 missense

Scores

11
5
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:8U:3

Conservation

PhyloP100: 1.65
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.923
PP5
Variant 1-46196047-G-A is Pathogenic according to our data. Variant chr1-46196047-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 558512.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Pathogenic=4, Likely_pathogenic=4}. Variant chr1-46196047-G-A is described in Lovd as [Likely_pathogenic]. Variant chr1-46196047-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
POMGNT1NM_017739.4 linkuse as main transcriptc.385C>T p.Arg129Trp missense_variant 5/22 ENST00000371984.8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
POMGNT1ENST00000371984.8 linkuse as main transcriptc.385C>T p.Arg129Trp missense_variant 5/221 NM_017739.4 P1Q8WZA1-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152110
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
GnomAD3 exomes
AF:
0.00000796
AC:
2
AN:
251224
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135842
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000137
AC:
20
AN:
1461726
Hom.:
0
Cov.:
31
AF XY:
0.0000165
AC XY:
12
AN XY:
727154
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000144
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152110
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74300
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:
0.000136
Hom.:
0
Bravo
AF:
0.0000378
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:8Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingGeneDxMay 25, 2022Residue is located within the carbohydrate-binding stem domain and has been shown to modulate O-mannosylation of the alpha-dystroglycan protein; disruptions of this position destabilize the POMGNT1 enzyme, leading to decreased catalytic activity (Kuwabara et al., 2016); 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: 34426522, 34324503, 28688748, 27493216, 30961548) -
Pathogenic, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenJul 01, 2023POMGNT1: PM3:Strong, PM1, PM2, PP3, PS3:Supporting -
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A3 Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingBaylor GeneticsMar 18, 2024- -
Likely pathogenic, criteria provided, single submitterclinical testingMyriad Genetics, Inc.Nov 08, 2021NM_017739.3(POMGNT1):c.385C>T(R129W) is a missense variant classified as likely pathogenic in the context of POMGNT-related disorders. R129W has been observed in cases with relevant disease (PMID: 28688748, 30961548, Kritioti_2019_(no PMID; abstract)). Functional assessments of this variant are not available in the literature. R129W has been observed in population frequency databases (gnomAD: NFE <0.001%). In summary, NM_017739.3(POMGNT1):c.385C>T(R129W) is a missense variant that has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -
Muscle eye brain disease Pathogenic:1Uncertain:1
Uncertain significance, no assertion criteria providedclinical testingNatera, Inc.Jan 31, 2020- -
Likely pathogenic, criteria provided, single submitterresearchCytogenetics and Genomics Lab, Cyprus Institute Of Neurology and GeneticsApr 10, 2020- -
Muscular dystrophy-dystroglycanopathy Pathogenic:1
Likely pathogenic, criteria provided, single submittercurationBroad Center for Mendelian Genomics, Broad Institute of MIT and HarvardJan 24, 2023The p.Arg129Trp variant in POMGNT1 has been reported in at least five individuals with POMGNT1-associated muscular dystrophy-dystroglycanopathy (PMID: 28688748, PMID: 30961548, PMID: 34324503, ClinVar SCV002029242.2), and has been identified in 0.002% (2/113568) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs375431575). 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 (Variation ID #558512) and has been interpreted as pathogenic by Invitae and CeGaT Center for Human Genetics Tuebingen, as likely pathogenic by Molecular Genetics (Royal Melbourne Hospital), Cytogenetics and Genomics Lab (Cyprus Institute Of Neurology and Genetics), and Myriad Women's Health, Inc., and as of uncertain significance by Counsyl, Illumina, and Natera, Inc. Of the five affected individuals, two were compound heterozygotes who carried a reported pathogenic or likely pathogenic variant in trans, which increases the likelihood that the p.Arg129Trp variant is pathogenic (PMID: 30961548, PMID: 34324503; ClinvarID: 56582, 984973). 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, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for POMGNT1-associated muscular dystrophy-dystroglycanopathy. ACMG/AMP Criteria applied: PM3_Strong, PM2_supporting, PP3 (Richards 2015). -
Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingInvitaeDec 06, 2023This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 129 of the POMGNT1 protein (p.Arg129Trp). This variant is present in population databases (rs375431575, gnomAD 0.003%). This missense change has been observed in individual(s) with muscular dystrophy-dystroglycanopathy or congenital muscular dystrophy (PMID: 28688748, 30961548, 34324503; 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: 558512). 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) performed at Invitae indicates that this missense variant is expected to disrupt POMGNT1 protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -
Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3 Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingMolecular Genetics, Royal Melbourne HospitalDec 02, 2021This sequence change in POMGNT1 is predicted to replace arginine with tryptophan at codon 129, p.(Arg129Trp). The arginine residue is highly conserved (100 vertebrates, UCSC), and is a critical carbohydrate binding residue in the interleukin-like EMT inducer (ILEI) domain (PMID: 27493216). There is a large physicochemical difference between arginine and tryptophan. The highest population minor allele frequency in gnomAD v2.1 is 0.002% (2/113,568 alleles) in the European (non-Finnish) population, which is consistent with a recessive condition. This variant has been detected in at least four individuals with muscular dystrophy-dystroglycanopathy. Of those individuals, three were compound heterozygous for the variant and a pathogenic or likely pathogenic variant and two of those were confirmed in trans by parental testing (PMID: 28688748, 30961548, 34324503). Further, the variant has been reported to segregate with disease in a single family (PMID: 34324503). Multiple lines of computational evidence predict a deleterious effect for the missense substitution (5/6 algorithms). Based on the classification scheme RMH Modified ACMG Guidelines v1.4.0, this variant is classified as LIKELY PATHOGENIC. Following criteria are met: PM3_Strong, PM1, PM2_Supporting, PP1, PP3. -
Autosomal recessive limb-girdle muscular dystrophy type 2O Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 2018This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Congenital Muscular Dystrophy, alpha-dystroglycan related Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 2018This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.96
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
31
DANN
Uncertain
1.0
DEOGEN2
Benign
0.29
T;D;.
Eigen
Uncertain
0.31
Eigen_PC
Benign
0.20
FATHMM_MKL
Uncertain
0.82
D
LIST_S2
Pathogenic
0.99
D;D;D
M_CAP
Pathogenic
0.29
D
MetaRNN
Pathogenic
0.92
D;D;D
MetaSVM
Uncertain
0.23
D
MutationAssessor
Uncertain
2.5
.;M;M
MutationTaster
Benign
1.0
D;D;D;D;D
PrimateAI
Pathogenic
0.91
D
PROVEAN
Pathogenic
-7.7
D;D;D
REVEL
Pathogenic
0.80
Sift
Pathogenic
0.0
D;D;D
Sift4G
Pathogenic
0.0
D;D;D
Polyphen
1.0
D;D;.
Vest4
0.96
MVP
0.91
MPC
0.91
ClinPred
1.0
D
GERP RS
2.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.92
gMVP
0.93

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

LitVar

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

Other links and lift over

dbSNP: rs375431575; hg19: chr1-46661719; COSMIC: COSV64340815; COSMIC: COSV64340815; API