Genetic Variant POMGNT1:p.Arg485His (chr1-46192183-C-T) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1PM5PP3BS1_Supporting

The NM_017739.4(POMGNT1):c.1454G>A(p.Arg485His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000743 in 1,614,164 control chromosomes in the GnomAD database, including 1 homozygotes. 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. R485C) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.00016 ( 1 hom., cov: 32)

Exomes 𝑓: 0.000066 ( 0 hom. )

Consequence

POMGNT1
NM_017739.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1

Conservation

PhyloP100: 7.22

Publications

0 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]

POMGNT1 links:

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]

TSPAN1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_017739.4

PM5

Other missense variant is known to change same aminoacid residue: Variant chr1-46192184-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1200851.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.792

BS1

Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000158 (24/152292) while in subpopulation AMR AF = 0.00111 (17/15296). AF 95% confidence interval is 0.000707. There are 1 homozygotes in GnomAd4. There are 14 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_017739.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
POMGNT1	NM_017739.4	MANE Select	c.1454G>A	p.Arg485His	missense	Exon 17 of 22	NP_060209.4
POMGNT1	NM_001243766.2		c.1454G>A	p.Arg485His	missense	Exon 17 of 23	NP_001230695.2
POMGNT1	NM_001410783.1		c.1454G>A	p.Arg485His	missense	Exon 17 of 22	NP_001397712.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
POMGNT1	ENST00000371984.8	TSL:1 MANE Select	c.1454G>A	p.Arg485His	missense	Exon 17 of 22	ENSP00000361052.3
POMGNT1	ENST00000371992.1	TSL:2	c.1454G>A	p.Arg485His	missense	Exon 17 of 23	ENSP00000361060.1
POMGNT1	ENST00000692369.1		c.1454G>A	p.Arg485His	missense	Exon 17 of 22	ENSP00000508453.1

Frequencies

GnomAD3 genomes

AF:

0.000164

AC:

AN:

152174

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00111

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000828

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.0000954

AC:

AN:

251496

AF XY:

0.000125

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000657

AC:

AN:

1461872

Hom.:

Cov.:

AF XY:

0.0000894

AC XY:

AN XY:

727242

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.000157

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.000904

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111998

Other (OTH)

AF:

0.0000828

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.000158

AC:

AN:

152292

Hom.:

Cov.:

AF XY:

0.000188

AC XY:

AN XY:

74464

show subpopulations

African (AFR)

AF:

0.0000481

AC:

AN:

41554

American (AMR)

AF:

0.00111

AC:

AN:

15296

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.000622

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68016

Other (OTH)

AF:

0.000473

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.505

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

Variant carriers

<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:

0.00

Hom.:

Bravo

AF:

0.000242

ExAC

AF:

0.0000741

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:4

Jul 28, 2020

Athena Diagnostics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

May 18, 2018

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Sep 15, 2021

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 24282183)

Jun 10, 2025

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Retinal dystrophy

Uncertain:1

Jan 01, 2020

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Muscle eye brain disease

Uncertain:1

Mar 17, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O

Benign:1

Dec 27, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.64

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Pathogenic

0.31

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.90

Eigen

Pathogenic

0.73

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

0.98

M_CAP

Uncertain

0.15

MetaRNN

Pathogenic

0.79

MetaSVM

Uncertain

0.47

MutationAssessor

Uncertain

2.2

PhyloP100

7.2

PrimateAI

Uncertain

0.75

PROVEAN

Uncertain

-4.0

REVEL

Pathogenic

0.82

Sift

Uncertain

0.0030

Sift4G

Uncertain

0.0080

Polyphen

1.0

Vest4

0.83

MutPred

0.83

Loss of MoRF binding (P = 0.0441)

MVP

0.92

MPC

0.99

ClinPred

0.66

GERP RS

4.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.72

gMVP

0.88

Mutation Taster

=13/87

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over