NM_033087.4:c.1132C>T

Variant names:

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_033087.4(ALG2):c.1132C>T(p.Arg378Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000573 in 1,614,126 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R378H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00051 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00058 ( 2 hom. )

Consequence

ALG2
NM_033087.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 4.40

Publications

4 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

ALG2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.07675636).

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000512 (78/152276) while in subpopulation AFR AF = 0.000914 (38/41560). AF 95% confidence interval is 0.000684. There are 0 homozygotes in GnomAd4. There are 35 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High Homozygotes in GnomAdExome4 at 2 AR,Unknown gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALG2	NM_033087.4 link	c.1132C>T	p.Arg378Cys	missense_variant	Exon 2 of 2	ENST00000476832.2	NP_149078.1	Q9H553-1A0A024R184
ALG2	XM_047423996.1 link	c.853C>T	p.Arg285Cys	missense_variant	Exon 2 of 2		XP_047279952.1
ALG2	NR_024532.2 link	n.1339C>T		non_coding_transcript_exon_variant	Exon 3 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
ALG2	ENST00000476832.2 link	c.1132C>T	p.Arg378Cys	missense_variant	Exon 2 of 2	1	NM_033087.4	ENSP00000417764.1	Q9H553-1
ALG2	ENST00000319033.7 link	c.853C>T	p.Arg285Cys	missense_variant	Exon 2 of 2	1		ENSP00000326609.6	Q9H553-2
ALG2	ENST00000238477.5 link	n.*874C>T		non_coding_transcript_exon_variant	Exon 3 of 3	2		ENSP00000432675.2	A0A0A0MTE0
ALG2	ENST00000238477.5 link	n.*874C>T		3_prime_UTR_variant	Exon 3 of 3	2		ENSP00000432675.2	A0A0A0MTE0

Frequencies

GnomAD3 genomes

AF:

0.000513

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000917

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000458

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:

0.000470

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.000346

AC:

AN:

251412

AF XY:

0.000309

show subpopulations

Gnomad AFR exome

AF:

0.00111

Gnomad AMR exome

AF:

0.000376

Gnomad ASJ exome

AF:

0.000198

Gnomad EAS exome

AF:

0.000109

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000413

Gnomad OTH exome

AF:

0.000326

GnomAD4 exome

AF:

0.000579

AC:

847

AN:

1461850

Hom.:

Cov.:

AF XY:

0.000518

AC XY:

377

AN XY:

727236

show subpopulations

African (AFR)

AF:

0.00140

AC:

AN:

33462

American (AMR)

AF:

0.000447

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.000115

AC:

AN:

26134

East Asian (EAS)

AF:

0.0000504

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000696

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000656

AC:

730

AN:

1112000

Other (OTH)

AF:

0.000646

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.459

Heterozygous variant carriers

147

196

245

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

128

160

<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:

0.000512

AC:

AN:

152276

Hom.:

Cov.:

AF XY:

0.000470

AC XY:

AN XY:

74452

show subpopulations

African (AFR)

AF:

0.000914

AC:

AN:

41560

American (AMR)

AF:

0.000457

AC:

AN:

15302

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000470

AC:

AN:

68020

Other (OTH)

AF:

0.000473

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.486

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000435

Hom.:

Bravo

AF:

0.000582

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00182

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.000305

AC:

EpiCase

AF:

0.000600

EpiControl

AF:

0.000415

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

ALG2-congenital disorder of glycosylation;C4015597:Congenital myasthenic syndrome 14

Uncertain:2

Jan 22, 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 cysteine, which is neutral and slightly polar, at codon 378 of the ALG2 protein (p.Arg378Cys). This variant is present in population databases (rs56393253, gnomAD 0.1%). 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: 265036). 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. -

Dec 27, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Inborn genetic diseases

Uncertain:1

Jul 12, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1132C>T (p.R378C) alteration is located in exon 2 (coding exon 2) of the ALG2 gene. This alteration results from a C to T substitution at nucleotide position 1132, causing the arginine (R) at amino acid position 378 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Jun 30, 2022

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported previously as a variant of uncertain significance identified with CDG molecular testing; however, no clinical information was provided (Jones et al., 2013); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 23806237) -

ALG2-congenital disorder of glycosylation

Uncertain:1

Jun 19, 2019

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.090

BayesDel_addAF

Benign

-0.29

BayesDel_noAF

Benign

-0.25

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.60

D;.

Eigen

Pathogenic

0.72

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Uncertain

0.86

LIST_S2

Benign

0.71

T;T

M_CAP

Benign

0.057

MetaRNN

Benign

0.077

T;T

MetaSVM

Uncertain

0.10

MutationAssessor

Uncertain

2.4

M;.

PhyloP100

4.4

PrimateAI

Benign

0.21

PROVEAN

Uncertain

-4.2

D;D

REVEL

Uncertain

0.37

Sift

Uncertain

0.016

D;D

Sift4G

Benign

0.099

T;D

Polyphen

0.99

D;D

Vest4

0.23

MVP

0.91

MPC

0.63

ClinPred

0.094

GERP RS

4.9

Varity_R

0.22

gMVP

0.51

Mutation Taster

=83/17

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over