22-33626300-G-T

Variant names:

• chr22-33626300-G-T
• rs86487
• NM_133642.5:c.435C>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_133642.5(LARGE1):​c.435C>A​(p.Ala145Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A145A) has been classified as Benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LARGE1 NM_133642.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0540
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• muscular dystrophy-dystroglycanopathy type B6

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A6

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• congenital muscular dystrophy with intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• muscular dystrophy-dystroglycanopathy, type A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.35).
• BP7: Synonymous conserved (PhyloP=-0.054 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_133642.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LARGE1	NM_133642.5	MANE Select	c.435C>A	p.Ala145Ala	synonymous	Exon 4 of 15	NP_598397.1
	LARGE1	NM_001362949.2		c.435C>A	p.Ala145Ala	synonymous	Exon 5 of 16	NP_001349878.1
	LARGE1	NM_001362951.2		c.435C>A	p.Ala145Ala	synonymous	Exon 4 of 15	NP_001349880.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LARGE1	ENST00000397394.8	TSL:5 MANE Select	c.435C>A	p.Ala145Ala	synonymous	Exon 4 of 15	ENSP00000380549.2
	LARGE1	ENST00000354992.7	TSL:1	c.435C>A	p.Ala145Ala	synonymous	Exon 5 of 16	ENSP00000347088.2
	LARGE1	ENST00000402320.6	TSL:1	c.435C>A	p.Ala145Ala	synonymous	Exon 4 of 14	ENSP00000385223.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 43

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.35
CADD	Benign	8.1
DANN	Benign	0.77
PhyloP100		-0.054
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs86487; hg19: chr22-34022284;