rs772370177

Positions:

• chr9-131509761-G-A
• chr9-131509761-G-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001077365.2(POMT1):​c.558G>A​(p.Trp186Ter) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: POMT1 NM_001077365.2 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 5.50

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-131509761-G-A is Pathogenic according to our data. Variant chr9-131509761-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 212739.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POMT1	NM_001077365.2	c.558G>A	p.Trp186Ter	stop_gained	7/20	ENST00000402686.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POMT1	ENST00000402686.8	c.558G>A	p.Trp186Ter	stop_gained	7/20	1	NM_001077365.2	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

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 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 09, 2022

This sequence change creates a premature translational stop signal (p.Trp186*) in the POMT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in POMT1 are known to be pathogenic (PMID: 12369018, 15637732, 16575835). 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: 212739). For these reasons, this variant has been classified as Pathogenic. -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1 Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Knight Diagnostic Laboratories, Oregon Health and Sciences University

Jul 29, 2014

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.62
CADD	Pathogenic	41
DANN	Uncertain	0.99
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	A;A;A;A;A;A;A;D
Vest4		0.77
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs772370177; hg19: chr9-134385148;