NM_017739.4:c.1011dupT

Variant names:

• chr1-46193578-C-CA
• rs751254522
• NM_017739.4:c.1011dupT

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PVS1 PP5

The NM_017739.4(POMGNT1):​c.1011dupT​(p.Asp338fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,864 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. I337I) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: POMGNT1 NM_017739.4 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:6 U:1
• Conservation: PhyloP100: -0.648
• Publications: 1 publications found

Genes affected

POMGNT1 (HGNC:19139): (protein O-linked mannose N-acetylglucosaminyltransferase 1 (beta 1,2-)) This gene encodes a type II transmembrane protein that resides in the Golgi apparatus. It participates in O-mannosyl glycosylation and is specific for alpha linked terminal mannose. Mutations in this gene may be associated with muscle-eye-brain disease and several congenital muscular dystrophies. Alternatively spliced transcript variants that encode different protein isoforms have been described. [provided by RefSeq, Feb 2014]

TSPAN1 (HGNC:20657): (tetraspanin 1) The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four hydrophobic domains. The proteins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 1-46193578-C-CA is Pathogenic according to our data. Variant chr1-46193578-C-CA is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 189099.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_017739.4. 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
	POMGNT1	NM_017739.4	MANE Select	c.1011dupT	p.Asp338fs	frameshift	Exon 11 of 22	NP_060209.4	Q8WZA1-1
	POMGNT1	NM_001243766.2		c.1011dupT	p.Asp338fs	frameshift	Exon 11 of 23	NP_001230695.2	Q8WZA1-2
	POMGNT1	NM_001410783.1		c.1011dupT	p.Asp338fs	frameshift	Exon 11 of 22	NP_001397712.1	A0A8I5KNB7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POMGNT1	ENST00000371984.8	TSL:1 MANE Select	c.1011dupT	p.Asp338fs	frameshift	Exon 11 of 22	ENSP00000361052.3	Q8WZA1-1
	POMGNT1	ENST00000371992.1	TSL:2	c.1011dupT	p.Asp338fs	frameshift	Exon 11 of 23	ENSP00000361060.1	Q8WZA1-2
	POMGNT1	ENST00000692369.1		c.1011dupT	p.Asp338fs	frameshift	Exon 11 of 22	ENSP00000508453.1	A0A8I5KNB7

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000199 AC: 5 AN: 251312 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000272

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461864 Hom.: 0 Cov.: 96 AF XY: 0.00000413 AC XY: 3 AN XY: 727226

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.000227 AC: 9 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112008

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000242 Hom.: 0

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
2	-	-	Muscle eye brain disease (2)
-	1	-	Muscular dystrophy-dystroglycanopathy (1)
1	-	-	Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A3 (1)
1	-	-	Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O (1)
1	-	-	POMGNT1-related disorder (1)
1	-	-	Retinal dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.65
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		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: rs751254522; hg19: chr1-46659250; COSMIC: COSV100915387; COSMIC: COSV100915387;