14-77320549-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_013382.7(POMT2):c.133C>G(p.Pro45Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. 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. P45L) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POMT2 NM_013382.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.248

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1341885).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POMT2	NM_013382.7	c.133C>G	p.Pro45Ala	missense_variant	1/21	ENST00000261534.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POMT2	ENST00000261534.9	c.133C>G	p.Pro45Ala	missense_variant	1/21	1	NM_013382.7	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 06, 2022

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. 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: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with POMT2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 45 of the POMT2 protein (p.Pro45Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.060
BayesDel_addAF	Benign	-0.0066	T
BayesDel_noAF	Benign	-0.25
Cadd	Benign	13
Dann	Benign	0.87
DEOGEN2	Benign	0.10	T
Eigen	Benign	-0.83
Eigen_PC	Benign	-0.67
FATHMM_MKL	Benign	0.62	D
LIST_S2	Benign	0.68	T
M_CAP	Uncertain	0.10	D
MetaRNN	Benign	0.13	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.97	L
MutationTaster	Benign	0.91	D
PrimateAI	Uncertain	0.68	T
PROVEAN	Benign	-0.49	N
REVEL	Benign	0.12
Sift	Benign	0.033	D
Sift4G	Benign	0.23	T
Polyphen		0.018	B
Vest4		0.10
MutPred		0.56		Loss of glycosylation at P45 (P = 0.0227);
MVP		0.51
MPC		0.080
ClinPred		0.098	T
GERP RS		2.2
Varity_R		0.036
gMVP		0.46

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr14-77786892;