1-1050785-G-C

Position:

• chr1-1050785-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_198576.4(AGRN):​c.5201G>C​(p.Arg1734Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. R1734C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: AGRN NM_198576.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.51

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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.908

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AGRN	NM_198576.4	c.5201G>C	p.Arg1734Pro	missense_variant	30/36	ENST00000379370.7	NP_940978.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AGRN	ENST00000379370.7	c.5201G>C	p.Arg1734Pro	missense_variant	30/36	1	NM_198576.4	ENSP00000368678.2
AGRN	ENST00000651234.1	c.4886G>C	p.Arg1629Pro	missense_variant	29/38			ENSP00000499046.1
AGRN	ENST00000652369.1	c.4886G>C	p.Arg1629Pro	missense_variant	29/35			ENSP00000498543.1
AGRN	ENST00000620552.4	c.4787G>C	p.Arg1596Pro	missense_variant	30/39	5		ENSP00000484607.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

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 19, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 955836). This variant has not been reported in the literature in individuals affected with AGRN-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 1734 of the AGRN protein (p.Arg1734Pro). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Pathogenic	27
DANN	Uncertain	0.99
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Pathogenic	0.51	D
MetaRNN	Pathogenic	0.91	D;D
MetaSVM	Uncertain	0.50	D
MutationAssessor	Pathogenic	3.0	M;.
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-5.0	D;.
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0020	D;.
Sift4G	Pathogenic	0.0	D;D
Vest4		0.85
MutPred		0.69		Loss of MoRF binding (P = 0.0239);.;
MVP		0.89
MPC		0.69
ClinPred		1.0	D
GERP RS		4.4
gMVP		0.93

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

Publications

LitVar

Other links and lift over

dbSNP: rs145444272; hg19: chr1-986165;