dbSNP rs771201662: POMT2:p.Pro220Ser (chr14-77301248-G-A) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_013382.7(POMT2):c.658C>T(p.Pro220Ser) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,848 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

POMT2
NM_013382.7 missense, splice_region

Scores

Splicing: ADA: 0.004701

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.79

Variant links:

Genes affected

POMT2 (HGNC:19743): (protein O-mannosyltransferase 2) The protein encoded by this gene is an O-mannosyltransferase that requires interaction with the product of the POMT1 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).[provided by RefSeq, Oct 2008]

POMT2 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POMT2	NM_013382.7 link	c.658C>T	p.Pro220Ser	missense_variant, splice_region_variant	Exon 6 of 21	ENST00000261534.9	NP_037514.2	Q9UKY4-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POMT2	ENST00000261534.9 link	c.658C>T	p.Pro220Ser	missense_variant, splice_region_variant	Exon 6 of 21	1	NM_013382.7	ENSP00000261534.4		Q9UKY4-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461848

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727232

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A2;C3150416:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B2;C3150418:Autosomal recessive limb-girdle muscular dystrophy type 2N

Uncertain:1

May 03, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline with serine at codon 220 of the POMT2 protein (p.Pro220Ser). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and serine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with POMT2-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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

0.18

BayesDel_addAF

Uncertain

0.071

BayesDel_noAF

Benign

-0.14

CADD

Uncertain

DANN

Benign

0.92

DEOGEN2

Uncertain

0.46

T;T

Eigen

Benign

0.12

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.86

D;D

M_CAP

Benign

0.081

MetaRNN

Uncertain

0.47

T;T

MetaSVM

Benign

-0.30

MutationAssessor

Benign

1.4

L;.

PrimateAI

Uncertain

0.50

PROVEAN

Uncertain

-2.9

D;D

REVEL

Uncertain

0.40

Sift

Benign

0.62

T;T

Sift4G

Benign

0.56

T;T

Polyphen

0.040

B;.

Vest4

0.32

MutPred

0.57

Gain of catalytic residue at W225 (P = 5e-04);.;

MVP

0.88

MPC

0.13

ClinPred

0.90

GERP RS

5.8

Varity_R

0.35

gMVP

0.52

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.0047

dbscSNV1_RF

Benign

0.052

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