chr1-1051326-G-C

Variant names:

• chr1-1051326-G-C
• rs757621899
• NM_198576.4:c.5327G>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_198576.4(AGRN):​c.5327G>C​(p.Arg1776Pro) variant causes a missense change. The variant allele was found at a frequency of 0.000000706 in 1,416,428 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1776C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: AGRN NM_198576.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.63
• 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: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.889

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AGRN	NM_198576.4	c.5327G>C	p.Arg1776Pro	missense_variant	Exon 31 of 36	ENST00000379370.7	NP_940978.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AGRN	ENST00000379370.7	c.5327G>C	p.Arg1776Pro	missense_variant	Exon 31 of 36	1	NM_198576.4	ENSP00000368678.2
AGRN	ENST00000651234.1	c.5024G>C	p.Arg1675Pro	missense_variant	Exon 31 of 38			ENSP00000499046.1
AGRN	ENST00000652369.2	c.5012G>C	p.Arg1671Pro	missense_variant	Exon 30 of 35			ENSP00000498543.1
AGRN	ENST00000620552.4	c.4925G>C	p.Arg1642Pro	missense_variant	Exon 32 of 39	5		ENSP00000484607.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.06e-7 AC: 1 AN: 1416428 Hom.: 0 Cov.: 37 AF XY: 0.00000143 AC XY: 1 AN XY: 700264

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 32792

American (AMR) AF: 0.00 AC: 0 AN: 37788

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25304

East Asian (EAS) AF: 0.00 AC: 0 AN: 37704

South Asian (SAS) AF: 0.00 AC: 0 AN: 80560

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48430

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5544

European-Non Finnish (NFE) AF: 9.18e-7 AC: 1 AN: 1089582

Other (OTH) AF: 0.00 AC: 0 AN: 58724

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Uncertain	24
DANN	Uncertain	0.99
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.89	D;D
MetaSVM	Uncertain	-0.014	T
PhyloP100		3.6
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-4.5	D;.
REVEL	Uncertain	0.58
Sift	Uncertain	0.0020	D;.
Sift4G	Pathogenic	0.0	D;D
Vest4		0.81
MVP		0.82
MPC		0.61
ClinPred		0.99	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
gMVP		0.88
Mutation Taster		=7/93	disease causing

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

Other links and lift over

dbSNP: rs757621899; hg19: chr1-986706;