NM_001077365.2:c.226G>C

Variant names:

• chr9-131506217-G-C
• NM_001077365.2:c.226G>C
• POMT1 p.Gly76Arg

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PS1_Very_Strong PM2 PP3_Strong

The NM_001077365.2(POMT1):​c.226G>C​(p.Gly76Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POMT1 NM_001077365.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.36
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, Genomics England PanelApp, G2P
• myopathy caused by variation in POMT1

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• autosomal recessive limb-girdle muscular dystrophy type 2K

  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
• congenital muscular dystrophy without 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: Pathogenic. The variant received 14 ACMG points.

• PS1: Transcript NM_001077365.2 (POMT1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.974

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001077365.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POMT1	NM_001077365.2	MANE Select	c.226G>C	p.Gly76Arg	missense	Exon 3 of 20	NP_001070833.1	A0A140VKE0
	POMT1	NM_001353193.2		c.226G>C	p.Gly76Arg	missense	Exon 3 of 20	NP_001340122.2	Q9Y6A1-1
	POMT1	NM_007171.4		c.226G>C	p.Gly76Arg	missense	Exon 3 of 20	NP_009102.4

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POMT1	ENST00000402686.8	TSL:1 MANE Select	c.226G>C	p.Gly76Arg	missense	Exon 3 of 20	ENSP00000385797.4	Q9Y6A1-2
	POMT1	ENST00000372228.9	TSL:1	c.226G>C	p.Gly76Arg	missense	Exon 3 of 20	ENSP00000361302.3	Q9Y6A1-1
	POMT1	ENST00000423007.6	TSL:1	c.226G>C	p.Gly76Arg	missense	Exon 2 of 19	ENSP00000404119.2	A0A1V1FTP4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.81	D
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Uncertain	0.65	D
MutationAssessor	Pathogenic	3.3	M
PhyloP100		9.4
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-2.5	D
REVEL	Pathogenic	0.81
Sift	Benign	0.033	D
Sift4G	Benign	0.063	T
Varity_R		0.93
gMVP		0.94
Mutation Taster		=0/100	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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr9-134381604;