rs1256837701

chr1-1041274-C-Gchr1-1041274-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_198576.4(AGRN):c.829C>G(p.Arg277Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000331 in 1,508,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R277C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000029 (0 hom.)
• Consequence: AGRN NM_198576.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.751

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10167658).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AGRN	NM_198576.4	c.829C>G	p.Arg277Gly	missense_variant	5/36	ENST00000379370.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AGRN	ENST00000379370.7	c.829C>G	p.Arg277Gly	missense_variant	5/36	1	NM_198576.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151934 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

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 AF: 0.00000295 AC: 4 AN: 1356818 Hom.: 0 Cov.: 33 AF XY: 0.00000597 AC XY: 4 AN XY: 669546

Gnomad4 AFR exome AF: 0.000106

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000130

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152042 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74338

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital myasthenic syndrome 8 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 23, 2023

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 277 of the AGRN protein (p.Arg277Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with AGRN-related conditions. ClinVar contains an entry for this variant (Variation ID: 948843). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
Cadd	Benign	17
Dann	Benign	0.59
Eigen	Benign	-0.90
Eigen_PC	Benign	-0.88
FATHMM_MKL	Benign	0.090	N
LIST_S2	Benign	0.53	T;T
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.10	T;T
MetaSVM	Benign	-0.95	T
MutationAssessor	Benign	-0.90	N;.
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-1.2	N;.
REVEL	Benign	0.11
Sift	Benign	0.49	T;.
Sift4G	Benign	0.38	T;T
Vest4		0.18
MutPred		0.39		Gain of catalytic residue at R277 (P = 0.0643);.;
MVP		0.68
MPC		1.0
ClinPred		0.16	T
GERP RS		1.4
gMVP		0.30

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: rs1256837701; hg19: chr1-976654;