15-32092916-T-G

Variant names:

• chr15-32092916-T-G
• rs6494212
• NM_000746.6:c.196-8387T>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000746.6(CHRNA7):​c.196-8387T>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000132 in 151,948 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 31)
• Consequence: CHRNA7 NM_000746.6 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.111
• Publications: 11 publications found

Genes affected

CHRNA7 (HGNC:1960): (cholinergic receptor nicotinic alpha 7 subunit) The nicotinic acetylcholine receptors (nAChRs) are members of a superfamily of ligand-gated ion channels that mediate fast signal transmission at synapses. The nAChRs are thought to be hetero-pentamers composed of homologous subunits. The proposed structure for each subunit is a conserved N-terminal extracellular domain followed by three conserved transmembrane domains, a variable cytoplasmic loop, a fourth conserved transmembrane domain, and a short C-terminal extracellular region. The protein encoded by this gene forms a homo-oligomeric channel, displays marked permeability to calcium ions and is a major component of brain nicotinic receptors that are blocked by, and highly sensitive to, alpha-bungarotoxin. Once this receptor binds acetylcholine, it undergoes an extensive change in conformation that affects all subunits and leads to opening of an ion-conducting channel across the plasma membrane. This gene is located in a region identified as a major susceptibility locus for juvenile myoclonic epilepsy and a chromosomal location involved in the genetic transmission of schizophrenia. An evolutionarily recent partial duplication event in this region results in a hybrid containing sequence from this gene and a novel FAM7A gene. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2012]

CHRNA7 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
• epilepsy

  Inheritance: Unknown Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHRNA7	NM_000746.6	c.196-8387T>G		intron_variant	Intron 2 of 9	ENST00000306901.9	NP_000737.1
CHRNA7	NM_001190455.3	c.283-8387T>G		intron_variant	Intron 2 of 9		NP_001177384.1
CHRNA7	NR_046324.1	n.308-8387T>G		intron_variant	Intron 2 of 7
CHRNA7	XM_011521178.4	c.196-8387T>G		intron_variant	Intron 2 of 8		XP_011519480.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHRNA7	ENST00000306901.9	c.196-8387T>G		intron_variant	Intron 2 of 9	1	NM_000746.6	ENSP00000303727.2

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151948 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.000576

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

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151948 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74204

African (AFR) AF: 0.00 AC: 0 AN: 41346

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.000576 AC: 2 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5168

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10584

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67958

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 56247

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	4.0
DANN	Benign	0.82
PhyloP100		-0.11

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: rs6494212; hg19: chr15-32385119;