NM_198576.4:c.4976+3C>G

Variant names:

• chr1-1050332-C-G
• rs113681205
• NM_198576.4:c.4976+3C>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_198576.4(AGRN):​c.4976+3C>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000659 in 151,748 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: AGRN NM_198576.4 splice_region, intron
• Scores: Splicing: ADA: 0.00002228
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.345
• Publications: 1 publications found

Genes affected

AGRN (HGNC:329): (agrin) This gene encodes one of several proteins that are critical in the development of the neuromuscular junction (NMJ), as identified in mouse knock-out studies. The encoded protein contains several laminin G, Kazal type serine protease inhibitor, and epidermal growth factor domains. Additional post-translational modifications occur to add glycosaminoglycans and disulfide bonds. In one family with congenital myasthenic syndrome affecting limb-girdle muscles, a mutation in this gene was found. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Mar 2015]

AGRN Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome 8

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
• presynaptic congenital myasthenic syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.62).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AGRN	NM_198576.4	c.4976+3C>G		splice_region_variant, intron_variant	Intron 28 of 35	ENST00000379370.7	NP_940978.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AGRN	ENST00000379370.7	c.4976+3C>G		splice_region_variant, intron_variant	Intron 28 of 35	1	NM_198576.4	ENSP00000368678.2
AGRN	ENST00000651234.1	c.4661+3C>G		splice_region_variant, intron_variant	Intron 27 of 37			ENSP00000499046.1
AGRN	ENST00000652369.2	c.4661+3C>G		splice_region_variant, intron_variant	Intron 27 of 34			ENSP00000498543.1
AGRN	ENST00000620552.4	c.4562+3C>G		splice_region_variant, intron_variant	Intron 28 of 38	5		ENSP00000484607.1

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151748 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: 0.000194

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 34

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151748 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74108

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41240

American (AMR) AF: 0.00 AC: 0 AN: 15268

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.000194 AC: 1 AN: 5152

South Asian (SAS) AF: 0.00 AC: 0 AN: 4796

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10596

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67912

Other (OTH) AF: 0.00 AC: 0 AN: 2086

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.62
CADD	Benign	13
DANN	Benign	0.53
PhyloP100		0.34

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000022
dbscSNV1_RF	Benign	0.076
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

Other links and lift over

dbSNP: rs113681205; hg19: chr1-985712;