rs139660235

Positions:

chr9-131510312-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_001077365.2(POMT1):c.752C>T(p.Pro251Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000285 in 1,614,070 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).

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

POMT1
NM_001077365.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:4

Conservation

PhyloP100: 7.33

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 Likely_pathogenic. Variant got 7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.979

PP5

Variant 9-131510312-C-T is Pathogenic according to our data. Variant chr9-131510312-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 95469.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=4}. Variant chr9-131510312-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POMT1	NM_001077365.2 linkuse as main transcript	c.752C>T	p.Pro251Leu	missense_variant	9/20	ENST00000402686.8	NP_001070833.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POMT1	ENST00000402686.8 linkuse as main transcript	c.752C>T	p.Pro251Leu	missense_variant	9/20	1	NM_001077365.2	ENSP00000385797	P1	Q9Y6A1-2

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000239

AC:

AN:

251468

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135908

show subpopulations

Gnomad AFR exome

AF:

0.000123

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:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000239

AC:

AN:

1461874

Hom.:

Cov.:

AF XY:

0.0000193

AC XY:

AN XY:

727234

show subpopulations

Gnomad4 AFR exome

AF:

0.000179

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000243

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000723

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000672

AC XY:

AN XY:

74352

show subpopulations

Gnomad4 AFR

AF:

0.000145

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:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000564

Hom.:

Bravo

AF:

0.0000756

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 16, 2024	Reported in a study on the pathogencity of variants associated with limb girdle muscular dystrophy; listed as variant seen in the Leiden Open Variation Database, but no additional information was provided (PMID: 25898921); 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: 34532947, 22522420, 25898921) -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Feb 07, 2013	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Mar 02, 2022	- -

Walker-Warburg congenital muscular dystrophy;C1836373:Autosomal recessive limb-girdle muscular dystrophy type 2K;C5436962:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 25, 2023

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 273 of the POMT1 protein (p.Pro273Leu). This variant is present in population databases (rs139660235, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of muscular dystrophy-dystroglycanopathy (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: 95469). 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 POMT1 protein function with a positive predictive value of 80%. 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. -

POMT1-related disorder

Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 01, 2023

The POMT1 c.818C>T variant is predicted to result in the amino acid substitution p.Pro273Leu. This variant was reported in an individual with Walker-Warburg syndrome (reported as c.997C>T (p.Pro273Leu) in Table S1, Willer et al. 2012. PubMed ID: 22522420; Varagur et al. 2022. PubMed ID: 34801143). This variant was also reported in the homozygous state in a fetus with hydrocephalus and additional brain malformations (See #28697; https://assises-genetique.org/sessions-de-posters-affiches/). This variant has also been associated with limb girdle muscular dystrophies, but further information was not available (Table S2, Di Fruscio et al. 2015. PubMed ID: 25898921). Functional studies in patient-derived fibroblast cell lines suggest that this variant might affect normal protein function (reported as POMT1-WWS in Figure 5 and Table S1, Willer et al. 2012. PubMed ID: 22522420). At PreventionGenetics, we have observed the c818C>T variant in the homozygous state in an individual with hydrocephalus and another patient in the compound heterozygous state with a clear pathogenic, loss-of-function variant POMT1 variant (internal data). This variant is reported in 0.016% of alleles in individuals of African descent in gnomAD and is interpreted as uncertain significance in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/95469/). We interpret this variant as likely pathogenic. -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 04, 2024

- -

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

Oct 31, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.79

BayesDel_addAF

Pathogenic

0.35

BayesDel_noAF

Pathogenic

0.51

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.86

.;.;D;.;D;.;.

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.69

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D;D;D;D;.;D

M_CAP

Pathogenic

0.39

MetaRNN

Pathogenic

0.98

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

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.3

.;.;.;.;H;.;.

MutationTaster

Benign

1.0

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

PrimateAI

Uncertain

0.58

PROVEAN

Pathogenic

-5.7

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

REVEL

Pathogenic

0.93

Sift

Uncertain

0.0070

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

Sift4G

Uncertain

0.017

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

Polyphen

1.0, 1.0

.;D;.;.;D;D;.

Vest4

0.89

MVP

0.99

MPC

0.90

ClinPred

0.99

GERP RS

5.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.81

gMVP

0.87

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