rs387906338

Variant names:

• chr1-63414136-TTAA-T
• rs387906338
• NM_013339.4:c.897_899delAAT

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM1 PM2 PM4_Supporting PP5_Very_Strong

The NM_013339.4(ALG6):​c.897_899delAAT​(p.Ile299del) variant causes a disruptive inframe deletion change. The variant allele was found at a frequency of 0.0000268 in 1,606,420 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: ALG6 NM_013339.4 disruptive_inframe_deletion
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 7.00

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 13 ACMG points.

• PM1: In a transmembrane_region Helical (size 20) in uniprot entity ALG6_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_013339.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_013339.4. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant 1-63414136-TTAA-T is Pathogenic according to our data. Variant chr1-63414136-TTAA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 30420.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-63414136-TTAA-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALG6	NM_013339.4	c.897_899delAAT	p.Ile299del	disruptive_inframe_deletion	Exon 10 of 15	ENST00000263440.6	NP_037471.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALG6	ENST00000263440.6	c.897_899delAAT	p.Ile299del	disruptive_inframe_deletion	Exon 10 of 15	5	NM_013339.4	ENSP00000263440.5

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152218 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000199 AC: 5 AN: 251236 Hom.: 0 AF XY: 0.0000294 AC XY: 4 AN XY: 135832

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000440

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000254 AC: 37 AN: 1454202 Hom.: 0 AF XY: 0.0000221 AC XY: 16 AN XY: 724014

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: 0.0000326

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152218 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74370

Gnomad4 AFR AF: 0.00

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: 0.0000882

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000264

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

ALG6-congenital disorder of glycosylation 1C Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Oct 19, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 10, 2024	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jul 01, 2000	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 19, 2025	This variant, c.897_899del, results in the deletion of 1 amino acid(s) of the ALG6 protein (p.Ile299del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs753111873, gnomAD 0.006%). This variant has been observed in individual(s) with congenital disorder of glycosylation 1c (PMID: 10924277, 27287710). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 30420). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:4

Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, Amsterdam University Medical Center	-	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Feb 21, 2022	In-frame deletion of one amino acid in a non-repeat region; Commonly identified and reported variant in patients with CDG-Ic (Hanefeld et al., 2000; Sun et al., 2005; Morava et al., 2006); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 10924277, 21811164, 10832578, 12855228, 16007612, 27287710, 27535533) -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs387906338; hg19: chr1-63879807;