rs757749808

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_017739.4(POMGNT1):c.1924A>T(p.Ile642Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,613,538 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I642V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

POMGNT1
NM_017739.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 2.27

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:):

TSPAN1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.3264625).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POMGNT1	NM_017739.4 linkuse as main transcript	c.1924A>T	p.Ile642Phe	missense_variant	22/22	ENST00000371984.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POMGNT1	ENST00000371984.8 linkuse as main transcript	c.1924A>T	p.Ile642Phe	missense_variant	22/22	1	NM_017739.4	P1	Q8WZA1-1

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

151908

Hom.:

Cov.:

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000200

AC:

AN:

250180

Hom.:

AF XY:

0.00000739

AC XY:

AN XY:

135400

show subpopulations

Gnomad AFR exome

AF:

0.0000618

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:

0.0000355

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000226

AC:

AN:

1461630

Hom.:

Cov.:

AF XY:

0.0000206

AC XY:

AN XY:

727108

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000270

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000132

AC:

AN:

151908

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74202

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 21, 2022

The c.1924A>T (p.I642F) alteration is located in exon 22 (coding exon 21) of the POMGNT1 gene. This alteration results from a A to T substitution at nucleotide position 1924, causing the isoleucine (I) at amino acid position 642 to be replaced by a phenylalanine (F). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 18, 2022

This sequence change replaces isoleucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 642 of the POMGNT1 protein (p.Ile642Phe). This variant is present in population databases (rs757749808, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with POMGNT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 586373). 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 not expected to disrupt POMGNT1 protein function. 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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jan 19, 2018

- -

Muscle eye brain disease

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Oct 28, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.23

BayesDel_addAF

Benign

-0.073

BayesDel_noAF

Benign

-0.56

Cadd

Benign

Dann

Uncertain

0.99

DEOGEN2

Uncertain

0.45

Eigen

Benign

-0.14

Eigen_PC

Benign

0.050

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.93

M_CAP

Benign

0.058

MetaRNN

Benign

0.33

MetaSVM

Benign

-1.1

MutationTaster

Benign

0.99

D;D;D;D;D

PROVEAN

Uncertain

-2.4

REVEL

Benign

0.17

Sift

Uncertain

0.0040

Sift4G

Uncertain

0.0050

Polyphen

0.93

Vest4

0.37

MutPred

0.15

Loss of sheet (P = 0.0457);

MVP

0.42

ClinPred

0.47

GERP RS

5.5

Varity_R

0.27

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

LitVar

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over