2-174753594-G-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_000079.4(CHRNA1):c.687C>A(p.Arg229=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R229R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CHRNA1 NM_000079.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0180

Genes affected

CHRNA1 (HGNC:1955): (cholinergic receptor nicotinic alpha 1 subunit) The muscle acetylcholine receptor consiststs of 5 subunits of 4 different types: 2 alpha subunits and 1 each of the beta, gamma, and delta subunits. This gene encodes an alpha subunit that plays a role in acetlycholine binding/channel gating. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Nov 2012]

(HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.58).
• BP7: Synonymous conserved (PhyloP=-0.018 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNA1	NM_000079.4	c.687C>A	p.Arg229=	synonymous_variant	6/9	ENST00000348749.9
CHRNA1	NM_001039523.3	c.762C>A	p.Arg254=	synonymous_variant	7/10
CHRNA1	XM_017003256.2	c.783C>A	p.Arg261=	synonymous_variant	6/9
CHRNA1	XM_017003257.2	c.708C>A	p.Arg236=	synonymous_variant	5/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNA1	ENST00000348749.9	c.687C>A	p.Arg229=	synonymous_variant	6/9	1	NM_000079.4	P1
	ENST00000442996.1	n.322-19155G>T		intron_variant, non_coding_transcript_variant		1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.58
Cadd	Benign	10
Dann	Benign	0.83

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: rs545520806; hg19: chr2-175618322;