rs539747006

chr22-33650587-T-Cchr22-33650587-T-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_133642.5(LARGE1):c.188A>G(p.Glu63Gly) variant causes a missense change. The variant allele was found at a frequency of 0.0000299 in 1,606,090 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. E63E) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000031 (0 hom.)
• Consequence: LARGE1 NM_133642.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 4.74

Genes affected

LARGE1 (HGNC:6511): (LARGE xylosyl- and glucuronyltransferase 1) This gene encodes a member of the N-acetylglucosaminyltransferase gene family. It encodes a glycosyltransferase which participates in glycosylation of alpha-dystroglycan, and may carry out the synthesis of glycoprotein and glycosphingolipid sugar chains. It may also be involved in the addition of a repeated disaccharide unit. The protein encoded by this gene is the glycotransferase that adds the final xylose and glucuronic acid to alpha-dystroglycan and thereby allows alpha-dystroglycan to bind ligands including laminin 211 and neurexin. Mutations in this gene cause several forms of congenital muscular dystrophy characterized by cognitive disability and abnormal glycosylation of alpha-dystroglycan. Alternative splicing of this gene results in multiple transcript variants that encode the same protein. [provided by RefSeq, May 2018]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.047675133).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LARGE1	NM_133642.5	c.188A>G	p.Glu63Gly	missense_variant	3/15	ENST00000397394.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LARGE1	ENST00000397394.8	c.188A>G	p.Glu63Gly	missense_variant	3/15	5	NM_133642.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152230 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: 0.000621

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000496 AC: 12 AN: 241902 Hom.: 0 AF XY: 0.0000455 AC XY: 6 AN XY: 131962

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: 0.000393

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000310 AC: 45 AN: 1453742 Hom.: 0 Cov.: 32 AF XY: 0.0000373 AC XY: 27 AN XY: 723638

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: 0.000429

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.000116

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152348 Hom.: 0 Cov.: 32 AF XY: 0.0000268 AC XY: 2 AN XY: 74506

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000622

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000508 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.0000660 AC: 8

Asia WGS AF: 0.000577 AC: 2 AN: 3478

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy type B6 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Feb 04, 2022	This sequence change replaces glutamic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 63 of the LARGE1 protein (p.Glu63Gly). This variant is present in population databases (rs539747006, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with LARGE1-related conditions. ClinVar contains an entry for this variant (Variation ID: 464471). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.094
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.18
Cadd	Uncertain	23
Dann	Uncertain	1.0
DEOGEN2	Benign	0.30	T;T;.;.;.;.
Eigen	Benign	-0.090
Eigen_PC	Benign	0.10
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Benign	0.0088	T
MetaRNN	Benign	0.048	T;T;T;T;T;T
MetaSVM	Benign	-0.99	T
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-1.4	N;N;N;D;D;D
REVEL	Benign	0.17
Sift	Uncertain	0.011	D;D;D;D;D;D
Sift4G	Benign	0.19	T;T;T;D;.;.
Polyphen		0.049	B;B;B;.;.;.
Vest4		0.47
MutPred		0.21		Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);
MVP		0.41
MPC		0.63
ClinPred		0.10	T
GERP RS		5.8
Varity_R		0.11
gMVP		0.47

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: rs539747006; hg19: chr22-34046573;