rs62031146

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP6_Very_StrongBS1BS2

The NM_000303.3(PMM2):​c.324G>A​(p.Ala108Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0163 in 1,612,270 control chromosomes in the GnomAD database, including 325 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. A108A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.013 ( 33 hom., cov: 33)
Exomes 𝑓: 0.017 ( 292 hom. )

Consequence

PMM2
NM_000303.3 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:12

Conservation

PhyloP100: -4.39

Publications

4 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: Benign. The variant received -16 ACMG points.

BP6
Variant 16-8806384-G-A is Benign according to our data. Variant chr16-8806384-G-A is described in ClinVar as Benign. ClinVar VariationId is 129976.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.0133 (2030/152282) while in subpopulation SAS AF = 0.0354 (171/4830). AF 95% confidence interval is 0.0311. There are 33 homozygotes in GnomAd4. There are 984 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 33 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PMM2NM_000303.3 linkc.324G>A p.Ala108Ala synonymous_variant Exon 4 of 8 ENST00000268261.9 NP_000294.1
PMM2XM_047434215.1 linkc.75G>A p.Ala25Ala synonymous_variant Exon 2 of 6 XP_047290171.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PMM2ENST00000268261.9 linkc.324G>A p.Ala108Ala synonymous_variant Exon 4 of 8 1 NM_000303.3 ENSP00000268261.4

Frequencies

GnomAD3 genomes
AF:
0.0133
AC:
2029
AN:
152164
Hom.:
33
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00531
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0172
Gnomad ASJ
AF:
0.0521
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.0352
Gnomad FIN
AF:
0.00396
Gnomad MID
AF:
0.0253
Gnomad NFE
AF:
0.0163
Gnomad OTH
AF:
0.0186
GnomAD2 exomes
AF:
0.0167
AC:
4190
AN:
251448
AF XY:
0.0180
show subpopulations
Gnomad AFR exome
AF:
0.00523
Gnomad AMR exome
AF:
0.0102
Gnomad ASJ exome
AF:
0.0481
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00522
Gnomad NFE exome
AF:
0.0175
Gnomad OTH exome
AF:
0.0181
GnomAD4 exome
AF:
0.0166
AC:
24178
AN:
1459988
Hom.:
292
Cov.:
29
AF XY:
0.0173
AC XY:
12534
AN XY:
726512
show subpopulations
African (AFR)
AF:
0.00586
AC:
196
AN:
33426
American (AMR)
AF:
0.0119
AC:
530
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0506
AC:
1322
AN:
26126
East Asian (EAS)
AF:
0.000101
AC:
4
AN:
39688
South Asian (SAS)
AF:
0.0337
AC:
2904
AN:
86202
European-Finnish (FIN)
AF:
0.00552
AC:
295
AN:
53398
Middle Eastern (MID)
AF:
0.0229
AC:
132
AN:
5766
European-Non Finnish (NFE)
AF:
0.0160
AC:
17741
AN:
1110326
Other (OTH)
AF:
0.0175
AC:
1054
AN:
60332
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.462
Heterozygous variant carriers
0
1091
2182
3273
4364
5455
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
670
1340
2010
2680
3350
<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:
0.0133
AC:
2030
AN:
152282
Hom.:
33
Cov.:
33
AF XY:
0.0132
AC XY:
984
AN XY:
74462
show subpopulations
African (AFR)
AF:
0.00534
AC:
222
AN:
41544
American (AMR)
AF:
0.0171
AC:
262
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.0521
AC:
181
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.0354
AC:
171
AN:
4830
European-Finnish (FIN)
AF:
0.00396
AC:
42
AN:
10618
Middle Eastern (MID)
AF:
0.0204
AC:
6
AN:
294
European-Non Finnish (NFE)
AF:
0.0163
AC:
1107
AN:
68024
Other (OTH)
AF:
0.0184
AC:
39
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
112
223
335
446
558
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
26
52
78
104
130
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0154
Hom.:
46
Bravo
AF:
0.0128
Asia WGS
AF:
0.0120
AC:
46
AN:
3478
EpiCase
AF:
0.0169
EpiControl
AF:
0.0183

ClinVar

Significance: Benign
Submissions summary: Benign:12
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:6
Feb 23, 2016
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Jun 17, 2015
Genomic Diagnostic Laboratory, Division of Genomic Diagnostics, Children's Hospital of Philadelphia
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Genetic Services Laboratory, University of Chicago
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

Likely benign based on allele frequency in 1000 Genomes Project or ESP global frequency and its presence in a patient with a rare or unrelated disease phenotype. NOT Sanger confirmed. -

-
Clinical Genetics, Academic Medical Center
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 25, 2017
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: The PMM2 c.324G>A (p.Ala108Ala) variant involves the alteration of a non-conserved nucleotide, resulting in a synonymous change. One in silico tool predicts a damaging outcome for this variant. 5/5 splice prediction tools predict no significant impact on normal splicing. ESE finder predicts that this variant may affect ESE site of SRp55. However, these predictions have yet to be confirmed by functional studies. This variant was found in 2137/121286 control chromosomes at a frequency of 0.0176195, which is approximately 3 times the estimated maximal expected allele frequency of a pathogenic PMM2 variant (0.0055902), suggesting this variant is likely a benign polymorphism. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as benign. Taken together, this variant is classified as benign. -

PMM2-congenital disorder of glycosylation Benign:5
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 16, 2020
Natera, Inc.
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Sep 21, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Benign:1
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.71
CADD
Benign
2.5
DANN
Benign
0.68
PhyloP100
-4.4
Mutation Taster
=99/1
polymorphism (auto)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.22
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.22
Position offset: 23

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

Publications

Other links and lift over

dbSNP: rs62031146; hg19: chr16-8900241; API