1-46192438-T-C

Variant names:

• chr1-46192438-T-C
• rs386834012
• NM_017739.4:c.1285-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1_Moderate PS3 PM2 PP5_Very_Strong

The NM_017739.4(POMGNT1):​c.1285-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,148 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV003761170: RT-PCR analysis performed on affected tissue shows intron retention and exon skipping (PMID:17030669).".

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: POMGNT1 NM_017739.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6 U:1
• Conservation: PhyloP100: 7.44
• 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: Pathogenic. The variant received 16 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.06505295 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV003761170: RT-PCR analysis performed on affected tissue shows intron retention and exon skipping (PMID: 17030669).
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-46192438-T-C is Pathogenic according to our data. Variant chr1-46192438-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 56578.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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.1285-2A>G		splice_acceptor intron	N/A	NP_060209.4	Q8WZA1-1
	POMGNT1	NM_001243766.2		c.1285-2A>G		splice_acceptor intron	N/A	NP_001230695.2	Q8WZA1-2
	POMGNT1	NM_001410783.1		c.1285-2A>G		splice_acceptor intron	N/A	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.1285-2A>G		splice_acceptor intron	N/A	ENSP00000361052.3	Q8WZA1-1
	POMGNT1	ENST00000371992.1	TSL:2	c.1285-2A>G		splice_acceptor intron	N/A	ENSP00000361060.1	Q8WZA1-2
	POMGNT1	ENST00000692369.1		c.1285-2A>G		splice_acceptor intron	N/A	ENSP00000508453.1	A0A8I5KNB7

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152148 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251248 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152148 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74338

African (AFR) AF: 0.00 AC: 0 AN: 41420

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.0000854 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2O (1)
1	-	-	Muscle eye brain disease (1)
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	-	-	Retinitis pigmentosa 76 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.20
CADD	Pathogenic	29
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.4
GERP RS		5.7
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AL_spliceai		1.0		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs386834012; hg19: chr1-46658110;