rs121912279

chr20-63349986-G-Achr20-63349986-G-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_Strong BP6_Moderate BP7 BS1

The NM_000744.7(CHRNA4):c.1425C>T(p.Gly475=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000213 in 1,550,652 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: CHRNA4 NM_000744.7 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1 O:2
• Conservation: PhyloP100: -4.66

Genes affected

CHRNA4 (HGNC:1958): (cholinergic receptor nicotinic alpha 4 subunit) This gene encodes a nicotinic acetylcholine receptor, which belongs to a superfamily of ligand-gated ion channels that play a role in fast signal transmission at synapses. These pentameric receptors can bind acetylcholine, which causes an extensive change in conformation that leads to the opening of an ion-conducting channel across the plasma membrane. This protein is an integral membrane receptor subunit that can interact with either nAChR beta-2 or nAChR beta-4 to form a functional receptor. Mutations in this gene cause nocturnal frontal lobe epilepsy type 1. Polymorphisms in this gene that provide protection against nicotine addiction have been described. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2012]

ACMG classification

Verdict is Benign. Variant got -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.93).
• BP6: Variant 20-63349986-G-A is Benign according to our data. Variant chr20-63349986-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 98317.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-4.66 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0000263 (4/152232) while in subpopulation AFR AF= 0.0000965 (4/41466). AF 95% confidence interval is 0.0000325. There are 0 homozygotes in gnomad4. There are 4 alleles in male gnomad4 subpopulation. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNA4	NM_000744.7	c.1425C>T	p.Gly475=	synonymous_variant	5/6	ENST00000370263.9
CHRNA4	NM_001256573.2	c.897C>T	p.Gly299=	synonymous_variant	5/6
CHRNA4	NR_046317.2	n.1634C>T		non_coding_transcript_exon_variant	5/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNA4	ENST00000370263.9	c.1425C>T	p.Gly475=	synonymous_variant	5/6	1	NM_000744.7	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152232 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000965

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000244 AC: 4 AN: 163642 Hom.: 0 AF XY: 0.0000226 AC XY: 2 AN XY: 88454

Gnomad AFR exome AF: 0.000108

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000468

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000147

Gnomad OTH exome AF: 0.000234

GnomAD4 exome AF: 0.0000207 AC: 29 AN: 1398420 Hom.: 0 Cov.: 83 AF XY: 0.0000290 AC XY: 20 AN XY: 688940

Gnomad4 AFR exome AF: 0.0000621

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000204

Gnomad4 OTH exome AF: 0.0000693

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152232 Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4 AN XY: 74370

Gnomad4 AFR AF: 0.0000965

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000128 Hom.: 0

Bravo AF: 0.0000264

ClinVar

Significance: Likely benign

Submissions summary: Benign:1 Other:2

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal dominant nocturnal frontal lobe epilepsy Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Apr 24, 2023

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Autosomal dominant nocturnal frontal lobe epilepsy 1 Other:1

not provided, no classification provided

phenotyping only

GenomeConnect - Brain Gene Registry

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Variant interpreted as Uncertain significance and reported on 08-24-2021 by Lab or GTR ID 500031. Assertions are reported exactly as they appear on the patient provided laboratory report. GenomeConnect does not attempt to reinterpret the variant. The IDDRC-CTSA National Brain Gene Registry (BGR ) is a study funded by the U.S. National Center for Advancing Translational Sciences (NCATS) and includes 13 Intellectual and Developmental Disability Research Center (IDDRC) institutions. The study is led by Principal Investigator John Constantino MD PhD from Washington University. The BGR is a data commons of gene variants paired with subject clinical information. This database helps scientists learn more about genetic changes and their impact on the brain and behavior. Participation in the Brain Gene Registry requires participation in GenomeConnect. -

Tobacco use disorder Other:1

not provided, no classification provided

literature only

Psychiatry Genetics Yale University

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.93
Cadd	Benign	0.075
Dann	Benign	0.65

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: rs121912279; hg19: chr20-61981338;