10-49627743-G-C

Variant names:

• chr10-49627743-G-C
• rs61731735
• NM_020549.5:c.1069G>C

Variant summary

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

The NM_020549.5(CHAT):​c.1069G>C​(p.Gly357Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,680 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: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CHAT NM_020549.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.51

Genes affected

CHAT (HGNC:1912): (choline O-acetyltransferase) This gene encodes an enzyme which catalyzes the biosynthesis of the neurotransmitter acetylcholine. This gene product is a characteristic feature of cholinergic neurons, and changes in these neurons may explain some of the symptoms of Alzheimer's disease. Polymorphisms in this gene have been associated with Alzheimer's disease and mild cognitive impairment. Mutations in this gene are associated with congenital myasthenic syndrome associated with episodic apnea. Multiple transcript variants encoding different isoforms have been found for this gene, and some of these variants have been shown to encode more than one isoform. [provided by RefSeq, May 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, 0.918

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHAT	NM_020549.5	c.1069G>C	p.Gly357Arg	missense_variant	Exon 7 of 15	ENST00000337653.7	NP_065574.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHAT	ENST00000337653.7	c.1069G>C	p.Gly357Arg	missense_variant	Exon 7 of 15	1	NM_020549.5	ENSP00000337103.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461680 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727150

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Nov 06, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CHAT c.1069G>C (p.Gly357Arg) results in a non-conservative amino acid change located in the Choline/carnitine acyltransferase domain (IPR039551) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251200 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1069G>C has been reported in the literature in the compound heterozygous state in two siblings suspected of Congenital Myasthenic Syndrome (Tan_2014). This report does not provide unequivocal conclusions about association of the variant with Congenital Myasthenic Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (http://dx.doi:10.1016/j.nmd.2014.06.169). ClinVar contains an entry for this variant (Variation ID: 1878399). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.54	.;.;.;D;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	.;.;D;D;D
M_CAP	Pathogenic	0.34	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D
MetaSVM	Uncertain	0.30	D
MutationAssessor	Uncertain	2.7	.;.;.;M;.
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-2.3	N;N;N;N;N
REVEL	Pathogenic	0.88
Sift	Benign	0.065	T;T;T;T;T
Sift4G	Benign	0.082	T;T;T;D;T
Polyphen		1.0	.;.;.;D;.
Vest4		0.90
MutPred		0.59		.;.;.;Gain of phosphorylation at S359 (P = 0.0736);.;
MVP		0.97
MPC		0.96
ClinPred		0.99	D
GERP RS		5.3
Varity_R		0.82
gMVP		0.73

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: rs61731735; hg19: chr10-50835789; COSMIC: COSV99045790; COSMIC: COSV99045790;