NM_033087.4:c.92G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_033087.4(ALG2):​c.92G>C​(p.Arg31Pro) variant causes a missense change. The variant allele was found at a frequency of 0.0000113 in 1,597,732 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. R31R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000097 ( 0 hom. )

Consequence

ALG2
NM_033087.4 missense

Scores

12
6
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.87

Publications

2 publications found
Variant links:
Genes affected
ALG2 (HGNC:23159): (ALG2 alpha-1,3/1,6-mannosyltransferase) This gene encodes a member of the glycosyltransferase 1 family. The encoded protein acts as an alpha 1,3 mannosyltransferase, mannosylating Man(2)GlcNAc(2)-dolichol diphosphate and Man(1)GlcNAc(2)-dolichol diphosphate to form Man(3)GlcNAc(2)-dolichol diphosphate. Defects in this gene have been associated with congenital disorder of glycosylation type Ih (CDG-Ii). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2008]
ALG2 Gene-Disease associations (from GenCC):
  • congenital myasthenic syndrome 14
    Inheritance: AR Classification: STRONG, MODERATE Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • ALG2-congenital disorder of glycosylation
    Inheritance: Unknown, AR Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P, PanelApp Australia, Orphanet, Ambry Genetics
  • congenital myasthenic syndromes with glycosylation defect
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.956

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ALG2NM_033087.4 linkc.92G>C p.Arg31Pro missense_variant Exon 1 of 2 ENST00000476832.2 NP_149078.1 Q9H553-1A0A024R184
ALG2NR_024532.2 linkn.140G>C non_coding_transcript_exon_variant Exon 1 of 3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ALG2ENST00000476832.2 linkc.92G>C p.Arg31Pro missense_variant Exon 1 of 2 1 NM_033087.4 ENSP00000417764.1 Q9H553-1
ALG2ENST00000238477.5 linkn.92G>C non_coding_transcript_exon_variant Exon 1 of 3 2 ENSP00000432675.2 A0A0A0MTE0

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152220
Hom.:
0
Cov.:
33
show subpopulations
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000969
AC:
14
AN:
1445512
Hom.:
0
Cov.:
32
AF XY:
0.00000973
AC XY:
7
AN XY:
719538
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33420
American (AMR)
AF:
0.00
AC:
0
AN:
44638
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26042
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39664
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86140
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
38484
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5660
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1111264
Other (OTH)
AF:
0.00
AC:
0
AN:
60200
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000263
AC:
4
AN:
152220
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
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:
0.0000588
AC:
4
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.563
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

ALG2-congenital disorder of glycosylation;C4015597:Congenital myasthenic syndrome 14 Uncertain:1
Feb 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 31 of the ALG2 protein (p.Arg31Pro). This variant is present in population databases (no rsID available, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with ALG2-related conditions. ClinVar contains an entry for this variant (Variation ID: 533479). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.43
D
BayesDel_noAF
Pathogenic
0.39
CADD
Pathogenic
30
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.66
D
Eigen
Pathogenic
0.87
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Pathogenic
0.77
D
MetaRNN
Pathogenic
0.96
D
MetaSVM
Uncertain
0.77
D
MutationAssessor
Pathogenic
3.8
H
PhyloP100
6.9
PrimateAI
Uncertain
0.74
T
PROVEAN
Pathogenic
-6.2
D
REVEL
Pathogenic
0.89
Sift
Pathogenic
0.0
D
Sift4G
Uncertain
0.0020
D
Polyphen
1.0
D
Vest4
0.91
MutPred
0.76
Loss of methylation at R31 (P = 0.1805);
MVP
0.92
MPC
0.90
ClinPred
1.0
D
GERP RS
4.7
PromoterAI
0.0012
Neutral
Varity_R
0.99
gMVP
0.96
Mutation Taster
=2/98
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: rs1279623882; hg19: chr9-101984085; API