8-42756276-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_004198.3(CHRNA6):c.923T>A(p.Leu308Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,268 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: CHRNA6 NM_004198.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.24

Genes affected

CHRNA6 (HGNC:15963): (cholinergic receptor nicotinic alpha 6 subunit) This gene encodes an alpha subunit of neuronal nicotinic acetylcholine receptors. These receptors consist of five subunits and function as ion channels involved in neurotransmission. The encoded protein is a subunit of neuronal nicotinic acetylcholine receptors that mediate dopaminergic neurotransmission and are activated by acetylcholine and exogenous nicotine. Alternatively spliced transcript variants have been observed for this gene. Single nucleotide polymorphisms in this gene have been associated with both nicotine and alcohol dependence. [provided by RefSeq, Dec 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.912

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNA6	NM_004198.3	c.923T>A	p.Leu308Gln	missense_variant	5/6	ENST00000276410.7
CHRNA6	NM_001199279.1	c.878T>A	p.Leu293Gln	missense_variant	4/5
CHRNA6	XM_047422396.1	c.923T>A	p.Leu308Gln	missense_variant	6/7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNA6	ENST00000276410.7	c.923T>A	p.Leu308Gln	missense_variant	5/6	1	NM_004198.3	P1
CHRNA6	ENST00000534622.5	c.878T>A	p.Leu293Gln	missense_variant	4/5	2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152268 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

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

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152268 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74396

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 05, 2024

The c.923T>A (p.L308Q) alteration is located in exon 5 (coding exon 5) of the CHRNA6 gene. This alteration results from a T to A substitution at nucleotide position 923, causing the leucine (L) at amino acid position 308 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.82	D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.91	D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	4.0	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-5.9	D;D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.96
MutPred		0.71		Loss of stability (P = 0.017);.;
MVP		0.97
MPC		0.55
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.96
gMVP		0.82

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: rs1264415609; hg19: chr8-42611419;