2-232544425-C-G

Position:

• chr2-232544425-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_005199.5(CHRNG):​c.1094C>G​(p.Ala365Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000089 in 1,461,294 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: CHRNG NM_005199.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.849

Genes affected

CHRNG (HGNC:1967): (cholinergic receptor nicotinic gamma subunit) The mammalian muscle-type acetylcholine receptor is a transmembrane pentameric glycoprotein with two alpha subunits, one beta, one delta, and one epsilon (in adult skeletal muscle) or gamma (in fetal and denervated muscle) subunit. This gene, which encodes the gamma subunit, is expressed prior to the thirty-third week of gestation in humans. The gamma subunit of the acetylcholine receptor plays a role in neuromuscular organogenesis and ligand binding and disruption of gamma subunit expression prevents the correct localization of the receptor in cell membranes. Mutations in this gene cause Escobar syndrome and a lethal form of multiple pterygium syndrome. Muscle-type acetylcholine receptor is the major antigen in the autoimmune disease myasthenia gravis.[provided by RefSeq, Sep 2009]

TIGD1 (HGNC:14523): (tigger transposable element derived 1) The protein encoded by this gene belongs to the tigger subfamily of the pogo superfamily of DNA-mediated transposons in humans. These proteins are related to DNA transposons found in fungi and nematodes, and more distantly to the Tc1 and mariner transposases. They are also very similar to the major mammalian centromere protein B. The exact function of this gene is not known. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.061751574).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHRNG	NM_005199.5	c.1094C>G	p.Ala365Gly	missense_variant	10/12	ENST00000651502.1
TIGD1	NM_145702.4	c.*3682G>C		3_prime_UTR_variant	1/1	ENST00000408957.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHRNG	ENST00000651502.1	c.1094C>G	p.Ala365Gly	missense_variant	10/12		NM_005199.5	P1
CHRNG	ENST00000389492.3	c.938C>G	p.Ala313Gly	missense_variant	9/11	1
TIGD1	ENST00000408957.7	c.*3682G>C		3_prime_UTR_variant	1/1		NM_145702.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000120 AC: 3 AN: 249328 Hom.: 0 AF XY: 0.0000222 AC XY: 3 AN XY: 135082

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000268

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000890 AC: 13 AN: 1461294 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 726976

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000312 Hom.: 0

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 27, 2024

The c.1094C>G (p.A365G) alteration is located in exon 10 (coding exon 10) of the CHRNG gene. This alteration results from a C to G substitution at nucleotide position 1094, causing the alanine (A) at amino acid position 365 to be replaced by a glycine (G). 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	Benign	0.089
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	0.15
DANN	Benign	0.60
DEOGEN2	Benign	0.13	T;.
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.045	N
LIST_S2	Benign	0.39	T;T
M_CAP	Benign	0.057	D
MetaRNN	Benign	0.062	T;T
MetaSVM	Benign	-0.83	T
MutationAssessor	Benign	0.66	N;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	0.010	N;N
REVEL	Benign	0.22
Sift	Benign	0.42	T;T
Sift4G	Benign	0.39	T;T
Polyphen		0.0	B;.
Vest4		0.095
MutPred		0.31		Gain of catalytic residue at P361 (P = 0.0833);.;
MVP		0.47
MPC		0.13
ClinPred		0.033	T
GERP RS		-1.1
Varity_R		0.057

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

Publications

LitVar

Other links and lift over

dbSNP: rs757694823; hg19: chr2-233409135;