1-1045235-A-G

Position:

• chr1-1045235-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_198576.4(AGRN):​c.2329A>G​(p.Asn777Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,038 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. N777H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: AGRN NM_198576.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.92

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.

• PM1: In a glycosylation_site N-linked (GlcNAc...) asparagine (size 0) in uniprot entity AGRIN_HUMAN
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AGRN	NM_198576.4	c.2329A>G	p.Asn777Asp	missense_variant	13/36	ENST00000379370.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AGRN	ENST00000379370.7	c.2329A>G	p.Asn777Asp	missense_variant	13/36	1	NM_198576.4	P1
AGRN	ENST00000651234.1	c.2014A>G	p.Asn672Asp	missense_variant	12/38
AGRN	ENST00000652369.1	c.2014A>G	p.Asn672Asp	missense_variant	12/35
AGRN	ENST00000620552.4	c.1915A>G	p.Asn639Asp	missense_variant	13/39	5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460038 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726312

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

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

Jun 27, 2022

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: "Benign"; Align-GVGD: "Class C0"). 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. ClinVar contains an entry for this variant (Variation ID: 567045). 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 asparagine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 777 of the AGRN protein (p.Asn777Asp). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.026	T
BayesDel_noAF	Benign	-0.27
CADD	Uncertain	24
DANN	Uncertain	0.99
Eigen	Uncertain	0.21
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Uncertain	0.61	D;D
MetaSVM	Benign	-0.39	T
MutationAssessor	Uncertain	2.7	M;.
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-2.8	D;.
REVEL	Uncertain	0.35
Sift	Benign	0.30	T;.
Sift4G	Uncertain	0.029	D;D
Vest4		0.52
MutPred		0.39		Gain of disorder (P = 0.1102);.;
MVP		0.77
MPC		0.24
ClinPred		0.81	D
GERP RS		3.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.9
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: rs777783441; hg19: chr1-980615;