rs779771679

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The NM_001077365.2(POMT1):c.724G>A(p.Ala242Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000304 in 1,614,050 control chromosomes in the GnomAD database, including 1 homozygotes. 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. A242V) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.000032 ( 1 hom. )

Consequence

POMT1
NM_001077365.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 5.24

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_001077365.2

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POMT1	NM_001077365.2 linkuse as main transcript	c.724G>A	p.Ala242Thr	missense_variant	9/20	ENST00000402686.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POMT1	ENST00000402686.8 linkuse as main transcript	c.724G>A	p.Ala242Thr	missense_variant	9/20	1	NM_001077365.2	P1	Q9Y6A1-2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152164

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:

0.0000278

AC:

AN:

251430

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135900

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:

0.000131

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000322

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.0000399

AC XY:

AN XY:

727248

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000267

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000198

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152164

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74340

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

Alfa

AF:

0.0000847

Hom.:

Bravo

AF:

0.0000227

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 08, 2023	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 -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Dec 01, 2016	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Feb 28, 2017

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Jul 06, 2021

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 18, 2022

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 264 of the POMT1 protein (p.Ala264Thr). This variant is present in population databases (rs779771679, gnomAD 0.01%). 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: 432550). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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

AlphaMissense

Benign

0.23

BayesDel_addAF

Benign

-0.044

BayesDel_noAF

Uncertain

-0.060

Cadd

Benign

Dann

Uncertain

1.0

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.53

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.89

D;D;D;D;D;.;T;D

M_CAP

Uncertain

0.15

MetaRNN

Uncertain

0.63

D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.66

MutationTaster

Benign

0.99

D;D;D;D;D;D;D;D

PrimateAI

Benign

0.48

PROVEAN

Benign

-1.6

N;N;N;N;N;N;N;D

REVEL

Uncertain

0.51

Sift

Benign

0.18

T;T;T;T;T;T;D;D

Sift4G

Benign

0.17

T;T;T;T;T;T;D;D

Polyphen

0.76, 1.0

.;P;.;.;D;P;.;.

Vest4

0.62

MutPred

0.75

.;.;.;.;Loss of methylation at R265 (P = 0.131);.;.;.;

MVP

0.95

MPC

0.88

ClinPred

0.38

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.12

gMVP

0.41

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.

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