1-63370981-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_013339.4(ALG6):c.4G>A(p.Glu2Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000329 in 152,082 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict 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. E2D) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.000033 (0 hom., cov: 32)
• Consequence: ALG6 NM_013339.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.33

Genes affected

ALG6 (HGNC:23157): (ALG6 alpha-1,3-glucosyltransferase) This gene encodes a member of the ALG6/ALG8 glucosyltransferase family. The encoded protein catalyzes the addition of the first glucose residue to the growing lipid-linked oligosaccharide precursor of N-linked glycosylation. Mutations in this gene are associated with congenital disorders of glycosylation type Ic. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2338379).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALG6	NM_013339.4	c.4G>A	p.Glu2Lys	missense_variant	2/15	ENST00000263440.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALG6	ENST00000263440.6	c.4G>A	p.Glu2Lys	missense_variant	2/15	5	NM_013339.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152082 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000121

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

GnomAD4 exome Cov.: 28

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152082 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74270

Gnomad4 AFR AF: 0.000121

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000227

ESP6500AA AF: 0.000454 AC: 2

ESP6500EA AF: 0.00 AC: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

ALG6-congenital disorder of glycosylation 1C Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 11, 2022

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 2 of the ALG6 protein (p.Glu2Lys). This variant is present in population databases (rs140944848, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with ALG6-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The lysine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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	Benign	0.13
BayesDel_addAF	Benign	-0.049	T
BayesDel_noAF	Benign	-0.31
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Benign	0.082	T;T
Eigen	Benign	-0.070
Eigen_PC	Benign	0.14
FATHMM_MKL	Uncertain	0.86	D
M_CAP	Benign	0.0085	T
MetaRNN	Benign	0.23	T;T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	1.1	L;L
MutationTaster	Benign	0.99	D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-1.4	N;N
REVEL	Benign	0.050
Sift	Uncertain	0.024	D;D
Sift4G	Uncertain	0.028	D;D
Vest4		0.19
MVP		0.77
MPC		0.34
ClinPred		0.86	D
GERP RS		4.8
Varity_R		0.15
gMVP		0.65

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs140944848; hg19: chr1-63836652;