22-49904451-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_024105.4(ALG12):​c.1048G>A​(p.Gly350Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000149 in 1,613,950 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. G350G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

ALG12
NM_024105.4 missense

Scores

4
8
7

Clinical Significance

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

Conservation

PhyloP100: 5.88

Publications

0 publications found
Variant links:
Genes affected
ALG12 (HGNC:19358): (ALG12 alpha-1,6-mannosyltransferase) This gene encodes a member of the glycosyltransferase 22 family. The encoded protein catalyzes the addition of the eighth mannose residue in an alpha-1,6 linkage onto the dolichol-PP-oligosaccharide precursor (dolichol-PP-Man(7)GlcNAc(2)) required for protein glycosylation. Mutations in this gene have been associated with congenital disorder of glycosylation type Ig (CDG-Ig)characterized by abnormal N-glycosylation. [provided by RefSeq, Jul 2008]
ALG12 Gene-Disease associations (from GenCC):
  • ALG12-congenital disorder of glycosylation
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, G2P, ClinGen, Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.877

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ALG12NM_024105.4 linkc.1048G>A p.Gly350Arg missense_variant Exon 8 of 10 ENST00000330817.11 NP_077010.1 Q9BV10A0A024R4V6
ALG12XM_017028936.2 linkc.1048G>A p.Gly350Arg missense_variant Exon 8 of 10 XP_016884425.1
ALG12XM_017028937.2 linkc.1048G>A p.Gly350Arg missense_variant Exon 8 of 11 XP_016884426.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ALG12ENST00000330817.11 linkc.1048G>A p.Gly350Arg missense_variant Exon 8 of 10 1 NM_024105.4 ENSP00000333813.5 Q9BV10
ALG12ENST00000486602.1 linkc.253G>A p.Gly85Arg missense_variant Exon 2 of 4 3 ENSP00000420630.1 H7C5R7
ENSG00000273192ENST00000610245.1 linkn.2224C>T non_coding_transcript_exon_variant Exon 1 of 1 6
ALG12ENST00000492791.1 linkn.522-67G>A intron_variant Intron 3 of 5 3 ENSP00000417387.1 H7C4I6

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152062
Hom.:
0
Cov.:
32
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251394
AF XY:
0.0000221
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000150
AC:
22
AN:
1461888
Hom.:
0
Cov.:
32
AF XY:
0.0000165
AC XY:
12
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.459
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:
0.0000132
AC:
2
AN:
152062
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74280
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41378
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
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:
0.0000151
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000247
AC:
3

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Sep 30, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: ALG12 c.1048G>A (p.Gly350Arg) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 251394 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.1048G>A in individuals affected with ALG12-Congenital Disorder Of Glycosylation and no experimental evidence demonstrating its impact on protein function have been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, citing the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

ALG12-congenital disorder of glycosylation Uncertain:1
Sep 15, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine with arginine at codon 350 of the ALG12 protein (p.Gly350Arg). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and arginine. This variant is present in population databases (rs377095724, ExAC 0.005%). This variant has not been reported in the literature in individuals affected with ALG12-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.75
BayesDel_addAF
Uncertain
0.053
T
BayesDel_noAF
Uncertain
-0.030
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.60
D
Eigen
Benign
0.11
Eigen_PC
Benign
0.015
FATHMM_MKL
Benign
0.71
D
LIST_S2
Uncertain
0.90
D
M_CAP
Benign
0.065
D
MetaRNN
Pathogenic
0.88
D
MetaSVM
Benign
-0.76
T
MutationAssessor
Pathogenic
3.1
M
PhyloP100
5.9
PrimateAI
Benign
0.38
T
PROVEAN
Pathogenic
-4.5
D
REVEL
Uncertain
0.41
Sift
Uncertain
0.0030
D
Sift4G
Uncertain
0.0040
D
Polyphen
1.0
D
Vest4
0.73
MutPred
0.85
Gain of MoRF binding (P = 0.0186);
MVP
0.82
MPC
0.66
ClinPred
0.95
D
GERP RS
4.8
Varity_R
0.83
gMVP
0.89
Mutation Taster
=85/15
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs377095724; hg19: chr22-50298099; COSMIC: COSV58208876; API