rs80338702

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000303.3(PMM2):​c.395T>A​(p.Ile132Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000887 in 1,578,324 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I132F) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000091 ( 0 hom. )

Consequence

PMM2
NM_000303.3 missense

Scores

14
3
2

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.85

Publications

22 publications found
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]
PMM2 Gene-Disease associations (from GenCC):
  • congenital disorder of glycosylation type I
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
  • PMM2-congenital disorder of glycosylation
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet, PanelApp Australia, ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1
In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000303.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr16-8811125-A-T is described in ClinVar as Pathogenic. ClinVar VariationId is 818203.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 89 curated pathogenic missense variants (we use a threshold of 10). The gene has 24 curated benign missense variants. Gene score misZ: -1.3872 (below the threshold of 3.09). Trascript score misZ: -1.8083 (below the threshold of 3.09). GenCC associations: The gene is linked to PMM2-congenital disorder of glycosylation, congenital disorder of glycosylation type I.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.994
PP5
Variant 16-8811126-T-A is Pathogenic according to our data. Variant chr16-8811126-T-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2736318.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PMM2NM_000303.3 linkc.395T>A p.Ile132Asn missense_variant Exon 5 of 8 ENST00000268261.9 NP_000294.1
PMM2XM_047434215.1 linkc.146T>A p.Ile49Asn missense_variant Exon 3 of 6 XP_047290171.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PMM2ENST00000268261.9 linkc.395T>A p.Ile132Asn missense_variant Exon 5 of 8 1 NM_000303.3 ENSP00000268261.4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152238
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000912
AC:
13
AN:
1426086
Hom.:
0
Cov.:
31
AF XY:
0.00000991
AC XY:
7
AN XY:
706112
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32728
American (AMR)
AF:
0.00
AC:
0
AN:
41550
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25492
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38520
South Asian (SAS)
AF:
0.00
AC:
0
AN:
82354
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50778
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5720
European-Non Finnish (NFE)
AF:
0.0000119
AC:
13
AN:
1090122
Other (OTH)
AF:
0.00
AC:
0
AN:
58822
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152238
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74388
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41466
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68048
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

PMM2-congenital disorder of glycosylation Pathogenic:1
Feb 07, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with asparagine, which is neutral and polar, at codon 132 of the PMM2 protein (p.Ile132Asn). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with congenital disorder of glycosylation type 1a (PMID: 10801058). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PMM2 protein function with a positive predictive value of 95%. This variant disrupts the p.Ile132 amino acid residue in PMM2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9497260, 15844218, 25355454, 29361989). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.40
D
BayesDel_noAF
Pathogenic
0.34
CADD
Pathogenic
28
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.92
D;D
Eigen
Pathogenic
0.72
Eigen_PC
Uncertain
0.59
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.37
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.7
.;H
PhyloP100
7.9
PrimateAI
Benign
0.41
T
PROVEAN
Pathogenic
-6.6
D;D
REVEL
Pathogenic
0.86
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
.;D
Vest4
0.96
MutPred
0.97
.;Gain of disorder (P = 0.0064);
MVP
0.97
MPC
0.041
ClinPred
0.99
D
GERP RS
5.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.95
gMVP
0.95
Mutation Taster
=4/96
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

Publications

Other links and lift over

dbSNP: rs80338702; hg19: chr16-8904983; API