chr2-174750000-G-T

Variant names:

• chr2-174750000-G-T
• rs141733086
• NM_000079.4:c.948C>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_Moderate BP6

The NM_000079.4(CHRNA1):​c.948C>A​(p.Ile316Ile) variant causes a synonymous change. The variant allele was found at a frequency of 0.000152 in 1,614,138 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00016 (0 hom.)
• Consequence: CHRNA1 NM_000079.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: 5.84
• Publications: 0 publications found

Genes affected

CHRNA1 (HGNC:1955): (cholinergic receptor nicotinic alpha 1 subunit) The muscle acetylcholine receptor consiststs of 5 subunits of 4 different types: 2 alpha subunits and 1 each of the beta, gamma, and delta subunits. This gene encodes an alpha subunit that plays a role in acetlycholine binding/channel gating. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Nov 2012]

CHRNA1 Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome 1A

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• myasthenic syndrome, congenital, 1B, fast-channel

  Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• lethal multiple pterygium syndrome

  Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000236449 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.34).
• BP6: Variant 2-174750000-G-T is Benign according to our data. Variant chr2-174750000-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 198389.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000079.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRNA1	NM_000079.4	MANE Select	c.948C>A	p.Ile316Ile	synonymous	Exon 7 of 9	NP_000070.1	Q53SH4
	CHRNA1	NM_001039523.3		c.1023C>A	p.Ile341Ile	synonymous	Exon 8 of 10	NP_001034612.1	P02708-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRNA1	ENST00000348749.9	TSL:1 MANE Select	c.948C>A	p.Ile316Ile	synonymous	Exon 7 of 9	ENSP00000261008.5	P02708-2
	ENSG00000236449	ENST00000442996.1	TSL:1	n.321+20176G>T		intron	N/A
	CHRNA1	ENST00000261007.9	TSL:2	c.1023C>A	p.Ile341Ile	synonymous	Exon 8 of 10	ENSP00000261007.5	P02708-1

Frequencies

GnomAD3 genomes AF: 0.000118 AC: 18 AN: 152138 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000262

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00949

Gnomad NFE AF: 0.000147

Gnomad OTH AF: 0.000479

GnomAD2 exomes AF: 0.000159 AC: 40 AN: 251256 AF XY: 0.000133

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000260

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000264

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000156 AC: 228 AN: 1461882 Hom.: 0 Cov.: 34 AF XY: 0.000135 AC XY: 98 AN XY: 727244

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.000246 AC: 11 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.000115 AC: 3 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.000520 AC: 3 AN: 5768

European-Non Finnish (NFE) AF: 0.000178 AC: 198 AN: 1112010

Other (OTH) AF: 0.000215 AC: 13 AN: 60394

GnomAD4 genome AF: 0.000118 AC: 18 AN: 152256 Hom.: 0 Cov.: 32 AF XY: 0.0000671 AC XY: 5 AN XY: 74464

African (AFR) AF: 0.00 AC: 0 AN: 41536

American (AMR) AF: 0.000262 AC: 4 AN: 15296

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5178

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.0102 AC: 3 AN: 294

European-Non Finnish (NFE) AF: 0.000147 AC: 10 AN: 68014

Other (OTH) AF: 0.000474 AC: 1 AN: 2110

Alfa AF: 0.0000853 Hom.: 0

Bravo AF: 0.000128

EpiCase AF: 0.000218

EpiControl AF: 0.000296

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	1	CHRNA1-related disorder (1)
-	-	1	Lethal multiple pterygium syndrome (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.34
CADD	Benign	12
DANN	Benign	0.88
PhyloP100		5.8
Mutation Taster		=86/14	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: rs141733086; hg19: chr2-175614728;