rs1339004837

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000303.3(PMM2):​c.190del​(p.Tyr64ThrfsTer11) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000137 in 1,460,342 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Y64Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

PMM2
NM_000303.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 3.60
Variant links:
Genes affected
PMM2 (HGNC:9115): (phosphomannomutase 2) The protein encoded by this gene catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate, which is a precursor to GDP-mannose necessary for the synthesis of dolichol-P-oligosaccharides. Mutations in this gene have been shown to cause defects in glycoprotein biosynthesis, which manifests as carbohydrate-deficient glycoprotein syndrome type I. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 16-8804777-AT-A is Pathogenic according to our data. Variant chr16-8804777-AT-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 554804.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-8804777-AT-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
PMM2NM_000303.3 linkuse as main transcriptc.190del p.Tyr64ThrfsTer11 frameshift_variant 3/8 ENST00000268261.9
PMM2XM_047434215.1 linkuse as main transcriptc.7-1538del intron_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
PMM2ENST00000268261.9 linkuse as main transcriptc.190del p.Tyr64ThrfsTer11 frameshift_variant 3/81 NM_000303.3 P1O15305-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251372
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135884
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1460342
Hom.:
0
Cov.:
29
AF XY:
0.00000138
AC XY:
1
AN XY:
726566
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:
0.00
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

PMM2-congenital disorder of glycosylation Pathogenic:5
Likely pathogenic, criteria provided, single submitterclinical testingBaylor GeneticsJan 24, 2024- -
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsJun 30, 2021- -
Pathogenic, criteria provided, single submitterclinical testingInvitaeNov 27, 2023This sequence change creates a premature translational stop signal (p.Tyr64Thrfs*11) in the PMM2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PMM2 are known to be pathogenic (PMID: 19862844). This variant is present in population databases (no rsID available, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with congenital disorders of glycosylation (PMID: 28139241). ClinVar contains an entry for this variant (Variation ID: 554804). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitterclinical testingCounsylNov 03, 2017- -
Likely pathogenic, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineFeb 10, 2024The p.Tyr64ThrfsX11 variant in PMM2 has been reported in 1 individual with congenital disorder of glycosylation, with no additional information about whether any other variants were identified (Perez-Cerda 2017 PMID: 28139241). This variant has also been reported by other clinical laboratories in ClinVar (Variation ID 554804) and was absent from large population studies (gnomAD v.3.1.2). This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 64 and leads to a premature termination codon 11 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Biallelic loss of function of the PMM2 gene is an established disease mechanism in autosomal recessive PMM2-congential disorder of glycosylation. In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal recessive PMM2-congential disorder of glycosylation. ACMG/AMP Criteria applied: PVS1, PM2_Supporting. -
PMM2-related disorder Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact SciencesSep 20, 2022The PMM2 c.190delT variant is predicted to result in a frameshift and premature protein termination (p.Tyr64Thrfs*11). This variant was reported in an individual with congenital disorder of glycosylation 1a (Pérez-Cerdá et al. 2017. PubMed ID: 28139241). This variant is reported in 0.0029% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/16-8898634-AT-A). Frameshift variants in PMM2 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.26
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.26
Position offset: -10

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: rs1339004837; hg19: chr16-8898634; API