chr14-77302855-C-G

Variant names:

• chr14-77302855-C-G
• rs368906346
• NM_013382.7:c.636G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_013382.7(POMT2):​c.636G>C​(p.Lys212Asn) 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 pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. K212K) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POMT2 NM_013382.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.38
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A2

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• myopathy caused by variation in POMT2

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B2

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• autosomal recessive limb-girdle muscular dystrophy type 2N

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• congenital muscular dystrophy with cerebellar involvement

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• congenital muscular dystrophy with intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• muscle-eye-brain disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.757

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POMT2	NM_013382.7	c.636G>C	p.Lys212Asn	missense_variant	Exon 5 of 21	ENST00000261534.9	NP_037514.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POMT2	ENST00000261534.9	c.636G>C	p.Lys212Asn	missense_variant	Exon 5 of 21	1	NM_013382.7	ENSP00000261534.4

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

Mar 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 212 of the POMT2 protein (p.Lys212Asn). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with POMT2-related conditions. ClinVar contains an entry for this variant (Variation ID: 1517625). 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 not expected to disrupt POMT2 protein function with a negative predictive value of 80%. 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	Pathogenic	0.82
BayesDel_addAF	Uncertain	0.064	T
BayesDel_noAF	Benign	-0.15
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D;D
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Benign	0.56	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.76	D;D
MetaSVM	Uncertain	0.57	D
MutationAssessor	Uncertain	2.5	M;.
PhyloP100		1.4
PrimateAI	Uncertain	0.69	T
PROVEAN	Uncertain	-3.6	D;D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.0090	D;D
Sift4G	Uncertain	0.015	D;D
Polyphen		0.99	D;.
Vest4		0.82
MutPred		0.62		Gain of catalytic residue at L208 (P = 6e-04);.;
MVP		0.91
MPC		0.48
ClinPred		0.98	D
GERP RS		4.6
PromoterAI		-0.00040	Neutral
Varity_R		0.79
gMVP		0.76
Mutation Taster		=48/52	disease causing

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

Other links and lift over

dbSNP: rs368906346; hg19: chr14-77769198;