1-1051598-A-G

Variant names:

• chr1-1051598-A-G
• rs1553178384
• NM_198576.4:c.5516A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_198576.4(AGRN):​c.5516A>G​(p.Tyr1839Cys) variant causes a missense change involving the alteration of a non-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 (★).

• Frequency: Genomes: not found (cov: 34)
• Consequence: AGRN NM_198576.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.80
• Publications: 0 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_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.978

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_198576.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AGRN	NM_198576.4	MANE Select	c.5516A>G	p.Tyr1839Cys	missense	Exon 32 of 36	NP_940978.2
	AGRN	NM_001305275.2		c.5528A>G	p.Tyr1843Cys	missense	Exon 33 of 39	NP_001292204.1
	AGRN	NM_001364727.2		c.5213A>G	p.Tyr1738Cys	missense	Exon 32 of 36	NP_001351656.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AGRN	ENST00000379370.7	TSL:1 MANE Select	c.5516A>G	p.Tyr1839Cys	missense	Exon 32 of 36	ENSP00000368678.2
	AGRN	ENST00000651234.1		c.5213A>G	p.Tyr1738Cys	missense	Exon 32 of 38	ENSP00000499046.1
	AGRN	ENST00000652369.2		c.5201A>G	p.Tyr1734Cys	missense	Exon 31 of 35	ENSP00000498543.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 86

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital myasthenic syndrome 8 Uncertain:1

Jun 20, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 1839 of the AGRN protein (p.Tyr1839Cys). 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: 474152). 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"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.43
CADD	Benign	22
DANN	Uncertain	0.99
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
PhyloP100		1.8
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-6.6	D
REVEL	Pathogenic	0.79
Sift	Uncertain	0.0020	D
Sift4G	Pathogenic	0.0010	D
Vest4		0.90
MVP		0.86
MPC		0.64
ClinPred		1.0	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
gMVP		0.87
Mutation Taster		=60/40	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1553178384; hg19: chr1-986978;