20-63346624-G-A

Variant names:

• chr20-63346624-G-A
• rs201354711
• ENST00000463705.5:n.2646C>T

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6_Moderate BS2

The NM_000744.7(CHRNA4):​c.*114C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000879 in 1,455,518 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.000079 (1 hom., cov: 33)
  • Exomes 𝑓: 0.000089 (0 hom.)
• Consequence: CHRNA4 NM_000744.7 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.641
• Publications: 0 publications found

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]

CHRNA4 Gene-Disease associations (from GenCC):

• autosomal dominant nocturnal frontal lobe epilepsy 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• familial sleep-related hypermotor epilepsy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• autosomal dominant nocturnal frontal lobe epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 20-63346624-G-A is Benign according to our data. Variant chr20-63346624-G-A is described in ClinVar as [Benign]. Clinvar id is 1291144.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAd4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA4	NM_000744.7	c.*114C>T		3_prime_UTR_variant	Exon 6 of 6	ENST00000370263.9	NP_000735.1
CHRNA4	NR_046317.2	n.2207C>T		non_coding_transcript_exon_variant	Exon 6 of 6
CHRNA4	NM_001256573.2	c.*114C>T		3_prime_UTR_variant	Exon 6 of 6		NP_001243502.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA4	ENST00000370263.9	c.*114C>T		3_prime_UTR_variant	Exon 6 of 6	1	NM_000744.7	ENSP00000359285.4

Frequencies

GnomAD3 genomes AF: 0.0000788 AC: 12 AN: 152194 Hom.: 1 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00228

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000247 AC: 34 AN: 137608 AF XY: 0.000295

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000240

GnomAD4 exome AF: 0.0000890 AC: 116 AN: 1303206 Hom.: 0 Cov.: 20 AF XY: 0.000131 AC XY: 85 AN XY: 646952

African (AFR) AF: 0.00 AC: 0 AN: 29868

American (AMR) AF: 0.00 AC: 0 AN: 35552

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24638

East Asian (EAS) AF: 0.00 AC: 0 AN: 35324

South Asian (SAS) AF: 0.00145 AC: 112 AN: 77382

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 33664

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4050

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1007614

Other (OTH) AF: 0.0000726 AC: 4 AN: 55114

GnomAD4 genome AF: 0.0000788 AC: 12 AN: 152312 Hom.: 1 Cov.: 33 AF XY: 0.000121 AC XY: 9 AN XY: 74482

African (AFR) AF: 0.00 AC: 0 AN: 41582

American (AMR) AF: 0.00 AC: 0 AN: 15300

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5170

South Asian (SAS) AF: 0.00228 AC: 11 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2110

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

Asia WGS AF: 0.00115 AC: 4 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Apr 29, 2020

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	4.0
DANN	Benign	0.80
PhyloP100		0.64
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs201354711; hg19: chr20-61977976;