rs745406424

Positions:

• chr1-1048234-C-G
• chr1-1048234-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_198576.4(AGRN):​c.3974C>G​(p.Ala1325Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000583 in 1,543,466 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. A1325A) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000058 (0 hom.)
• Consequence: AGRN NM_198576.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.764

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.049154997).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AGRN	NM_198576.4	c.3974C>G	p.Ala1325Gly	missense_variant	23/36	ENST00000379370.7	NP_940978.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AGRN	ENST00000379370.7	c.3974C>G	p.Ala1325Gly	missense_variant	23/36	1	NM_198576.4	ENSP00000368678.2
AGRN	ENST00000651234.1	c.3659C>G	p.Ala1220Gly	missense_variant	22/38			ENSP00000499046.1
AGRN	ENST00000652369.1	c.3659C>G	p.Ala1220Gly	missense_variant	22/35			ENSP00000498543.1
AGRN	ENST00000620552.4	c.3560C>G	p.Ala1187Gly	missense_variant	23/39	5		ENSP00000484607.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152174 Hom.: 0 Cov.: 32

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: 0.00000575 AC: 8 AN: 1391292 Hom.: 0 Cov.: 35 AF XY: 0.00000729 AC XY: 5 AN XY: 685494

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000275

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000651

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152174 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74350

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

Bravo AF: 0.00000378

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

Labcorp Genetics (formerly Invitae), Labcorp

Jul 17, 2022

This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 1325 of the AGRN protein (p.Ala1325Gly). 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: 541171). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The glycine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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	-0.25	T
BayesDel_noAF	Benign	-0.59
CADD	Benign	0.013
DANN	Benign	0.19
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.013	N
LIST_S2	Benign	0.57	T;T
M_CAP	Uncertain	0.10	D
MetaRNN	Benign	0.049	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.97	N;.
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.090	N;.
REVEL	Benign	0.063
Sift	Benign	0.81	T;.
Sift4G	Benign	0.46	T;T
Vest4		0.082
MutPred		0.24		Gain of catalytic residue at A1325 (P = 0.1184);.;
MVP		0.60
MPC		0.12
ClinPred		0.025	T
GERP RS		-3.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
gMVP		0.21

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: rs745406424; hg19: chr1-983614; COSMIC: COSV65070813; COSMIC: COSV65070813;