chr3-184245199-T-C

Variant names:

• chr3-184245199-T-C
• rs1553828635
• NM_005787.6:c.604A>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_005787.6(ALG3):​c.604A>G​(p.Ser202Gly) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. 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. S202R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ALG3 NM_005787.6 missense, splice_region
• Scores: Splicing: ADA: 0.9998
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.99
• Publications: 0 publications found

Genes affected

ALG3 (HGNC:23056): (ALG3 alpha-1,3- mannosyltransferase) This gene encodes a member of the ALG3 family. The encoded protein catalyses the addition of the first dol-P-Man derived mannose in an alpha 1,3 linkage to Man5GlcNAc2-PP-Dol. Defects in this gene have been associated with congenital disorder of glycosylation type Id (CDG-Id) characterized by abnormal N-glycosylation. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2008]

ALG3 Gene-Disease associations (from GenCC):

• ALG3-congenital disorder of glycosylation

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, ClinGen, PanelApp Australia, Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 16 curated pathogenic missense variants (we use a threshold of 10). The gene has 5 curated benign missense variants. Gene score misZ: -0.31675 (below the threshold of 3.09). Trascript score misZ: 0.74965 (below the threshold of 3.09). GenCC associations: The gene is linked to ALG3-congenital disorder of glycosylation.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALG3	NM_005787.6	c.604A>G	p.Ser202Gly	missense_variant, splice_region_variant	Exon 4 of 9	ENST00000397676.8	NP_005778.1
ALG3	NM_001006941.2	c.460A>G	p.Ser154Gly	missense_variant, splice_region_variant	Exon 4 of 9		NP_001006942.1
ALG3	NR_024533.1	n.535A>G		splice_region_variant, non_coding_transcript_exon_variant	Exon 3 of 8
ALG3	NR_024534.1	n.598A>G		splice_region_variant, non_coding_transcript_exon_variant	Exon 4 of 9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALG3	ENST00000397676.8	c.604A>G	p.Ser202Gly	missense_variant, splice_region_variant	Exon 4 of 9	1	NM_005787.6	ENSP00000380793.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461576 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727062

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44702

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86226

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53382

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111834

Other (OTH) AF: 0.00 AC: 0 AN: 60368

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Jun 03, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.604A>G (p.S202G) alteration is located in exon 4 (coding exon 4) of the ALG3 gene. This alteration results from a A to G substitution at nucleotide position 604, causing the serine (S) at amino acid position 202 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.53
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.73	D;.;.
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.96	D;D;D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	3.2	M;.;.
PhyloP100		8.0
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.7	D;D;D
REVEL	Pathogenic	0.96
Sift	Uncertain	0.0080	D;D;D
Sift4G	Uncertain	0.0080	D;D;D
Polyphen		0.93	P;.;D
Vest4		0.89
MutPred		0.84		Loss of stability (P = 0.0223);.;.;
MVP		0.98
MPC		0.39
ClinPred		0.99	D
GERP RS		4.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.78
gMVP		0.82
Mutation Taster		=11/89	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.59		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.59		Position offset: -1

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

Other links and lift over

dbSNP: rs1553828635; hg19: chr3-183962987;