X-111681261-G-A

Variant names:

• chrX-111681261-G-A
• rs776133794
• NM_001099922.3:c.43G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001099922.3(ALG13):​c.43G>A​(p.Asp15Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000364 in 1,098,097 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. 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. D15Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 24)
  • Exomes 𝑓: 0.0000036 (0 hom. 1 hem.)
• Consequence: ALG13 NM_001099922.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.46
• Publications: 1 publications found

Genes affected

ALG13 (HGNC:30881): (ALG13 UDP-N-acetylglucosaminyltransferase subunit) The protein encoded by this gene is a subunit of a bipartite UDP-N-acetylglucosamine transferase. It heterodimerizes with asparagine-linked glycosylation 14 homolog to form a functional UDP-GlcNAc glycosyltransferase that catalyzes the second sugar addition of the highly conserved oligosaccharide precursor in endoplasmic reticulum N-linked glycosylation. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2009]

ALG13 Gene-Disease associations (from GenCC):

• genetic developmental and epileptic encephalopathy

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy, 36

  Inheritance: XL Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• non-syndromic X-linked intellectual disability

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALG13	NM_001099922.3	c.43G>A	p.Asp15Asn	missense_variant	Exon 1 of 27	ENST00000394780.8	NP_001093392.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALG13	ENST00000394780.8	c.43G>A	p.Asp15Asn	missense_variant	Exon 1 of 27	2	NM_001099922.3	ENSP00000378260.3

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD2 exomes AF: 0.0000109 AC: 2 AN: 183176 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000366

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000364 AC: 4 AN: 1098097 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 1 AN XY: 363459

African (AFR) AF: 0.00 AC: 0 AN: 26401

American (AMR) AF: 0.0000284 AC: 1 AN: 35196

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19384

East Asian (EAS) AF: 0.00 AC: 0 AN: 30198

South Asian (SAS) AF: 0.0000185 AC: 1 AN: 54134

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40500

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4136

European-Non Finnish (NFE) AF: 0.00000238 AC: 2 AN: 842059

Other (OTH) AF: 0.00 AC: 0 AN: 46089

GnomAD4 genome Cov.: 24

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 36 Uncertain:1

Aug 26, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 15 of the ALG13 protein (p.Asp15Asn). This variant is present in population databases (rs776133794, gnomAD 0.005%). This variant has not been reported in the literature in individuals affected with ALG13-related conditions. ClinVar contains an entry for this variant (Variation ID: 847615). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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	0.20
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.39
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Benign	0.21	.;T;T;.;T
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;D;D;D;D
M_CAP	Pathogenic	0.72	D
MetaRNN	Uncertain	0.50	D;D;D;D;D
MetaSVM	Uncertain	-0.20	T
MutationAssessor	Benign	1.6	L;L;.;.;.
PhyloP100		6.5
PrimateAI	Uncertain	0.48	T
PROVEAN	Benign	-1.9	N;N;.;.;.
REVEL	Uncertain	0.29
Sift	Benign	0.10	T;D;.;.;.
Sift4G	Benign	0.35	T;T;T;T;T
Polyphen		0.45	B;D;.;.;.
Vest4		0.34
MutPred		0.42		Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);Loss of helix (P = 0.2022);.;
MVP		0.88
MPC		0.41
ClinPred		0.64	D
GERP RS		4.4
PromoterAI		-0.093	Neutral
Varity_R		0.27
gMVP		0.42
Mutation Taster		=81/19	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs776133794; hg19: chrX-110924489; COSMIC: COSV99322622; COSMIC: COSV99322622;