rs199541666

Variant names:

• chr20-63359671-G-A
• rs199541666
• NM_000744.7:c.105C>T

Your query was ambiguous. Multiple possible variants found:

• chr20-63359671-G-A
• chr20-63359671-G-C
• chr20-63359671-G-T

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_Strong BP6_Very_Strong BS2

The NM_001256573.2(CHRNA4):​c.-442C>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000205 in 1,611,596 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 0.000013 (0 hom., cov: 34)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: CHRNA4 NM_001256573.2 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: -1.61
• Publications: 1 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 -16 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.67).
• BP6: Variant 20-63359671-G-A is Benign according to our data. Variant chr20-63359671-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 384137.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS2: High AC in GnomAdExome4 at 31 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001256573.2. 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
	CHRNA4	NM_000744.7	MANE Select	c.105C>T	p.His35His	synonymous	Exon 2 of 6	NP_000735.1
	CHRNA4	NM_001256573.2		c.-442C>T		5_prime_UTR_premature_start_codon_gain	Exon 2 of 6	NP_001243502.1
	CHRNA4	NM_001256573.2		c.-442C>T		5_prime_UTR	Exon 2 of 6	NP_001243502.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRNA4	ENST00000370263.9	TSL:1 MANE Select	c.105C>T	p.His35His	synonymous	Exon 2 of 6	ENSP00000359285.4
	CHRNA4	ENST00000467563.3	TSL:1	n.157C>T		non_coding_transcript_exon	Exon 2 of 6
	CHRNA4	ENST00000627000.1	TSL:1	n.105C>T		non_coding_transcript_exon	Exon 2 of 6	ENSP00000486914.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152236 Hom.: 0 Cov.: 34

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: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000120 AC: 3 AN: 249358 AF XY: 0.0000148

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: 0.0000267

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000212 AC: 31 AN: 1459242 Hom.: 0 Cov.: 37 AF XY: 0.0000165 AC XY: 12 AN XY: 725954

African (AFR) AF: 0.0000598 AC: 2 AN: 33448

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86208

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52004

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4926

European-Non Finnish (NFE) AF: 0.0000261 AC: 29 AN: 1111858

Other (OTH) AF: 0.00 AC: 0 AN: 60254

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152354 Hom.: 0 Cov.: 34 AF XY: 0.0000134 AC XY: 1 AN XY: 74500

African (AFR) AF: 0.00 AC: 0 AN: 41572

American (AMR) AF: 0.00 AC: 0 AN: 15314

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

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

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68036

Other (OTH) AF: 0.00 AC: 0 AN: 2114

Alfa AF: 0.00 Hom.: 0

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions as Germline

Significance: Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Autosomal dominant nocturnal frontal lobe epilepsy (1)
-	-	1	Inborn genetic diseases (1)
-	-	1	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.67
CADD	Benign	1.3
DANN	Benign	0.93
PhyloP100		-1.6

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: rs199541666; hg19: chr20-61991023;