9-99218786-G-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBS1_Supporting

The NM_033087.4(ALG2):c.399C>G(p.Ile133Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000261 in 1,611,548 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

ALG2
NM_033087.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.897

Publications

0 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: Likely_benign. The variant received -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.23039293).

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000138 (21/152148) while in subpopulation AFR AF = 0.000507 (21/41410). AF 95% confidence interval is 0.000339. There are 0 homozygotes in GnomAd4. There are 10 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein
ALG2	NM_033087.4 link	c.399C>G	p.Ile133Met	missense_variant	Exon 2 of 2	ENST00000476832.2	NP_149078.1
ALG2	XM_047423996.1 link	c.120C>G	p.Ile40Met	missense_variant	Exon 2 of 2		XP_047279952.1
ALG2	NR_024532.2 link	n.606C>G		non_coding_transcript_exon_variant	Exon 3 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
ALG2	ENST00000476832.2 link	c.399C>G	p.Ile133Met	missense_variant	Exon 2 of 2	1	NM_033087.4	ENSP00000417764.1
ALG2	ENST00000319033.7 link	c.120C>G	p.Ile40Met	missense_variant	Exon 2 of 2	1		ENSP00000326609.6
ALG2	ENST00000238477.5 link	n.*141C>G		non_coding_transcript_exon_variant	Exon 3 of 3	2		ENSP00000432675.2
ALG2	ENST00000238477.5 link	n.*141C>G		3_prime_UTR_variant	Exon 3 of 3	2		ENSP00000432675.2

Frequencies

GnomAD3 genomes

AF:

0.000138

AC:

AN:

152148

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000507

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

GnomAD2 exomes

AF:

0.0000442

AC:

AN:

248874

AF XY:

0.0000520

show subpopulations

Gnomad AFR exome

AF:

0.000681

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000144

AC:

AN:

1459400

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

726076

show subpopulations

African (AFR)

AF:

0.000568

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50964

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111998

Other (OTH)

AF:

0.0000166

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.480

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.000138

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

74332

show subpopulations

African (AFR)

AF:

0.000507

AC:

AN:

41410

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5204

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68018

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.496

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:

0.000142

Hom.:

Bravo

AF:

0.000159

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000494

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Sep 06, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.399C>G (p.I133M) alteration is located in exon 2 (coding exon 2) of the ALG2 gene. This alteration results from a C to G substitution at nucleotide position 399, causing the isoleucine (I) at amino acid position 133 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

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

Uncertain:1

Jul 16, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant has not been reported in the literature in individuals affected with ALG2-related conditions. This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 133 of the ALG2 protein (p.Ile133Met). This variant is present in population databases (rs371772900, gnomAD 0.07%). ClinVar contains an entry for this variant (Variation ID: 533478). 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: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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

Uncertain

0.38

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.20

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.50

T;.

Eigen

Uncertain

0.48

Eigen_PC

Uncertain

0.41

FATHMM_MKL

Uncertain

0.79

LIST_S2

Uncertain

0.97

D;D

M_CAP

Uncertain

0.14

MetaRNN

Benign

0.23

T;T

MetaSVM

Uncertain

0.12

MutationAssessor

Uncertain

2.7

M;.

PhyloP100

0.90

PrimateAI

Uncertain

0.50

PROVEAN

Benign

-2.2

N;N

REVEL

Uncertain

0.51

Sift

Uncertain

0.0020

D;D

Sift4G

Uncertain

0.0030

D;D

Vest4

0.29

ClinPred

0.26

GERP RS

2.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.73

gMVP

0.90

Mutation Taster

=87/13

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