rs141089495

Positions:

• chr22-33277171-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PM2 BP4_Moderate BP6 BP7 BS1

The NM_133642.5(LARGE1):​c.1962G>A​(p.Glu654=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00112 in 1,614,144 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0012 (0 hom.)
• Consequence: LARGE1 NM_133642.5 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:3
• Conservation: PhyloP100: 0.467

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 -6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.27).
• BP6: Variant 22-33277171-C-T is Benign according to our data. Variant chr22-33277171-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 194517.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=3, Likely_benign=3}. Variant chr22-33277171-C-T is described in Lovd as [Likely_benign].
• BP7: Synonymous conserved (PhyloP=0.467 with no splicing effect.
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000657 (100/152254) while in subpopulation NFE AF= 0.00106 (72/68050). AF 95% confidence interval is 0.000861. There are 0 homozygotes in gnomad4. There are 58 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LARGE1	NM_133642.5	c.1962G>A	p.Glu654=	synonymous_variant	14/15	ENST00000397394.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LARGE1	ENST00000397394.8	c.1962G>A	p.Glu654=	synonymous_variant	14/15	5	NM_133642.5	P1

Frequencies

GnomAD3 genomes AF: 0.000657 AC: 100 AN: 152254 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000785

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.000471

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00106

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.000629 AC: 158 AN: 251388 Hom.: 0 AF XY: 0.000640 AC XY: 87 AN XY: 135866

Gnomad AFR exome AF: 0.000431

Gnomad AMR exome AF: 0.000145

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000323

Gnomad NFE exome AF: 0.00121

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.00117 AC: 1715 AN: 1461890 Hom.: 0 Cov.: 32 AF XY: 0.00115 AC XY: 837 AN XY: 727246

Gnomad4 AFR exome AF: 0.000209

Gnomad4 AMR exome AF: 0.000134

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.000337

Gnomad4 NFE exome AF: 0.00146

Gnomad4 OTH exome AF: 0.00101

GnomAD4 genome AF: 0.000657 AC: 100 AN: 152254 Hom.: 0 Cov.: 32 AF XY: 0.000780 AC XY: 58 AN XY: 74394

Gnomad4 AFR AF: 0.000241

Gnomad4 AMR AF: 0.000785

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000471

Gnomad4 NFE AF: 0.00106

Gnomad4 OTH AF: 0.000478

Alfa AF: 0.000932 Hom.: 0

Bravo AF: 0.000597

EpiCase AF: 0.00147

EpiControl AF: 0.000948

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	May 19, 2015	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jan 01, 2022	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 08, 2021	- -

Muscular dystrophy-dystroglycanopathy type B6 Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 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. -
Likely benign, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	- -

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 13, 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
BayesDel_noAF	Benign	-0.27
CADD	Benign	5.8
DANN	Benign	0.66

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: rs141089495; hg19: chr22-33673157;