22-33273192-T-C

Position:

• chr22-33273192-T-C

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_Moderate BP6_Moderate BS1 BS2

The NM_133642.5(LARGE1):​c.*1235A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00268 in 389,310 control chromosomes in the GnomAD database, including 12 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0053 (11 hom., cov: 32)
  • Exomes 𝑓: 0.00097 (1 hom.)
• Consequence: LARGE1 NM_133642.5 3_prime_UTR
• Clinical Significance: Likely benign criteria provided, single submitter B:2
• Conservation: PhyloP100: 3.19

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]

LARGE1 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.24).
• BP6: Variant 22-33273192-T-C is Benign according to our data. Variant chr22-33273192-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 341411.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00533 (812/152322) while in subpopulation AFR AF= 0.0183 (760/41584). AF 95% confidence interval is 0.0172. There are 11 homozygotes in gnomad4. There are 374 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 11 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LARGE1	NM_133642.5	c.*1235A>G		3_prime_UTR_variant	15/15	ENST00000397394.8	NP_598397.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LARGE1	ENST00000397394	c.*1235A>G		3_prime_UTR_variant	15/15	5	NM_133642.5	ENSP00000380549.2

Frequencies

GnomAD3 genomes AF: 0.00533 AC: 811 AN: 152204 Hom.: 11 Cov.: 32

Gnomad AFR AF: 0.0183

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00131

Gnomad ASJ AF: 0.00461

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000118

Gnomad OTH AF: 0.00335

GnomAD4 exome AF: 0.000971 AC: 230 AN: 236988 Hom.: 1 Cov.: 0 AF XY: 0.000840 AC XY: 101 AN XY: 120246

Gnomad4 AFR exome AF: 0.0165

Gnomad4 AMR exome AF: 0.00182

Gnomad4 ASJ exome AF: 0.00594

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000138

Gnomad4 OTH exome AF: 0.00166

GnomAD4 genome AF: 0.00533 AC: 812 AN: 152322 Hom.: 11 Cov.: 32 AF XY: 0.00502 AC XY: 374 AN XY: 74486

Gnomad4 AFR AF: 0.0183

Gnomad4 AMR AF: 0.00131

Gnomad4 ASJ AF: 0.00461

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000118

Gnomad4 OTH AF: 0.00331

Alfa AF: 0.00247 Hom.: 0

Bravo AF: 0.00562

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy type B6 Benign:1

Likely benign, 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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

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

Likely benign, 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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.24
CADD	Benign	15
DANN	Benign	0.91

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: rs1801820; hg19: chr22-33669178;