NM_013339.4:c.281G>A

Variant names:

• chr1-63404476-G-A
• rs1644480834
• NM_013339.4:c.281G>A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_013339.4(ALG6):​c.281G>A​(p.Trp94*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,408 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ALG6 NM_013339.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.24

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 Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-63404476-G-A is Pathogenic according to our data. Variant chr1-63404476-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 2799271.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALG6	NM_013339.4	c.281G>A	p.Trp94*	stop_gained	Exon 5 of 15	ENST00000263440.6	NP_037471.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALG6	ENST00000263440.6	c.281G>A	p.Trp94*	stop_gained	Exon 5 of 15	5	NM_013339.4	ENSP00000263440.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461408 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727010

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

ALG6-congenital disorder of glycosylation 1C Pathogenic:1

Jan 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Trp94*) in the ALG6 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ALG6 are known to be pathogenic (PMID: 19862844). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ALG6-related conditions. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	44
DANN	Uncertain	1.0
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.87
GERP RS		5.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.25		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.25		Position offset: -23

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

Publications

LitVar

Other links and lift over

dbSNP: rs1644480834; hg19: chr1-63870147;