rs984288781

Positions:

• chr9-131519442-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001077365.2(POMT1):​c.1540G>A​(p.Val514Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000258 in 1,551,478 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: POMT1 NM_001077365.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.122

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 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0345937).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POMT1	NM_001077365.2	c.1540G>A	p.Val514Ile	missense_variant	16/20	ENST00000402686.8	NP_001070833.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POMT1	ENST00000402686.8	c.1540G>A	p.Val514Ile	missense_variant	16/20	1	NM_001077365.2	ENSP00000385797.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32

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: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000214 AC: 3 AN: 1399314 Hom.: 0 Cov.: 32 AF XY: 0.00000145 AC XY: 1 AN XY: 690200

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000278

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000185

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74332

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Labcorp Genetics (formerly Invitae), Labcorp

Mar 23, 2022

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 536 of the POMT1 protein (p.Val536Ile). This variant is not present in population databases (gnomAD no frequency). 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: 568485). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The isoleucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	0.0060
DANN	Benign	0.75
DEOGEN2	Benign	0.15	.;.;.;T;.;T
Eigen	Benign	-2.1
Eigen_PC	Benign	-2.1
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.69	T;T;T;T;.;T
M_CAP	Benign	0.075	D
MetaRNN	Benign	0.035	T;T;T;T;T;T
MetaSVM	Benign	-0.78	T
MutationAssessor	Benign	-0.045	.;.;.;N;.;.
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-0.31	N;N;N;N;N;N
REVEL	Benign	0.20
Sift	Benign	0.48	T;T;T;T;T;T
Sift4G	Benign	0.60	T;T;T;T;T;T
Polyphen		0.0	.;B;.;B;B;.
Vest4		0.22
MutPred		0.25		.;.;.;Loss of sheet (P = 0.1398);.;.;
MVP		0.27
MPC		0.20
ClinPred		0.048	T
GERP RS		-11
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.011
gMVP		0.095

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

Other links and lift over

dbSNP: rs984288781; hg19: chr9-134394829;