rs376753193

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_001077365.2(POMT1):​c.122+5G>A variant causes a splice donor 5th base, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000185 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

POMT1
NM_001077365.2 splice_donor_5th_base, intron

Scores

2
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 8.56
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
POMT1NM_001077365.2 linkuse as main transcriptc.122+5G>A splice_donor_5th_base_variant, intron_variant ENST00000402686.8 NP_001070833.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
POMT1ENST00000402686.8 linkuse as main transcriptc.122+5G>A splice_donor_5th_base_variant, intron_variant 1 NM_001077365.2 ENSP00000385797 P1Q9Y6A1-2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251380
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135892
show subpopulations
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1461884
Hom.:
0
Cov.:
31
AF XY:
0.0000138
AC XY:
10
AN XY:
727242
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000234
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000171
Hom.:
0
Bravo
AF:
0.00000756
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Walker-Warburg congenital muscular dystrophy;C1836373:Autosomal recessive limb-girdle muscular dystrophy type 2K;C5436962:Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B1 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpAug 20, 2021This sequence change falls in intron 2 of the POMT1 gene. It does not directly change the encoded amino acid sequence of the POMT1 protein. It affects a nucleotide within the consensus splice site of the intron. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with type II lissencephaly (PMID: 17559086). ClinVar contains an entry for this variant (Variation ID: 285653). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jan 08, 2016- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.32
CADD
Benign
22
DANN
Benign
0.95

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
1.0
SpliceAI score (max)
0.89
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.89
Position offset: -5

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs376753193; hg19: chr9-134379732; API