rs794727931

Positions:

• chr11-78112692-A-C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_024079.5(ALG8):​c.856T>G​(p.Trp286Gly) variant causes a missense 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. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ALG8 NM_024079.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 U:1
• Conservation: PhyloP100: 8.66

Genes affected

ALG8 (HGNC:23161): (ALG8 alpha-1,3-glucosyltransferase) This gene encodes a member of the ALG6/ALG8 glucosyltransferase family. The encoded protein catalyzes the addition of the second glucose residue to the lipid-linked oligosaccharide precursor for N-linked glycosylation of proteins. Mutations in this gene have been associated with congenital disorder of glycosylation type Ih (CDG-Ih). Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 11-78112692-A-C is Pathogenic according to our data. Variant chr11-78112692-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 198905.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALG8	NM_024079.5	c.856T>G	p.Trp286Gly	missense_variant	8/13	ENST00000299626.10	NP_076984.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALG8	ENST00000299626.10	c.856T>G	p.Trp286Gly	missense_variant	8/13	1	NM_024079.5	ENSP00000299626	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

ALG8 congenital disorder of glycosylation Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Centre for Arab Genomic Studies, Sheikh Hamdan Award for Medical Sciences	Jul 15, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 04, 2023	This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tryptophan, which is neutral and slightly polar, with glycine, which is neutral and non-polar, at codon 286 of the ALG8 protein (p.Trp286Gly). This missense change has been observed in individual(s) with clinical features of ALG8-congenital disorder of glycosylation (PMID: 23806237, 28940310; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 198905). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ALG8 protein function. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1 Uncertain:1

Uncertain significance, flagged submission	clinical testing	Eurofins Ntd Llc (ga)	Jun 28, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 18, 2024	Not observed at significant frequency in large population cohorts (gnomAD); 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, 28940310, 35716054) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	31
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.87	D;.;.;D;D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	D;.;D;D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.2	H;H;H;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.79	T
PROVEAN	Pathogenic	-12	D;D;.;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;.;.
Polyphen		1.0	D;.;.;.;.
Vest4		0.97
MutPred		0.92		Loss of stability (P = 0.0786);Loss of stability (P = 0.0786);Loss of stability (P = 0.0786);.;.;
MVP		0.99
MPC		0.87
ClinPred		1.0	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.92

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

LitVar

Other links and lift over

dbSNP: rs794727931; hg19: chr11-77823738;