chr10-49620535-G-A

Position:

chr10-49620535-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2PP3_ModeratePP5_Very_Strong

The NM_020549.5(CHAT):c.620G>A(p.Arg207His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,613,648 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

CHAT
NM_020549.5 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 9.92

Variant links:

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]

CHAT links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.927

PP5

Variant 10-49620535-G-A is Pathogenic according to our data. Variant chr10-49620535-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 289944.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-49620535-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHAT	NM_020549.5 linkuse as main transcript	c.620G>A	p.Arg207His	missense_variant	4/15	ENST00000337653.7	NP_065574.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHAT	ENST00000337653.7 linkuse as main transcript	c.620G>A	p.Arg207His	missense_variant	4/15	1	NM_020549.5	ENSP00000337103	P2	P28329-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000966

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

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

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251416

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135888

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461526

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727088

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

0.00000540

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152122

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74304

show subpopulations

Gnomad4 AFR

AF:

0.0000966

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000378

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Familial infantile myasthenia

Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Nov 28, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 11, 2023	This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 207 of the CHAT protein (p.Arg207His). This variant is present in population databases (rs764497513, gnomAD 0.007%). This missense change has been observed in individuals with congenital myasthenic syndrome (PMID: 26080897). ClinVar contains an entry for this variant (Variation ID: 289944). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CHAT protein function. Experimental studies have shown that this missense change affects CHAT function (PMID: 26080897). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genomic Research Center, Shahid Beheshti University of Medical Sciences	Jul 20, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Nov 12, 2015	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Aug 16, 2016

- -

Congenital myasthenic syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Aug 07, 2024

Variant summary: CHAT c.620G>A (p.Arg207His) results in a non-conservative amino acid change located in the Choline/carnitine acyltransferase domain (IPR039551) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251416 control chromosomes. c.620G>A has been reported in the literature in individuals affected with Congenital Myasthenic Syndrome (Arredondo_2016). These data indicate that the variant is likely to be associated with disease. In transfected HEK293 cells, the variant had 81% expression levels as compared to wild-type, but only 3% catalytic efficiency (Arredondo_2016). The most pronounced variant effect results in <10% of normal activity. The following publication has been ascertained in the context of this evaluation (PMID: 26080897). ClinVar contains an entry for this variant (Variation ID: 289944). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.32

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.37

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.85

.;.;.;D;.

Eigen

Pathogenic

0.98

Eigen_PC

Pathogenic

0.93

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

.;.;D;D;D

M_CAP

Uncertain

0.12

MetaRNN

Pathogenic

0.93

D;D;D;D;D

MetaSVM

Pathogenic

0.85

MutationAssessor

Pathogenic

3.5

.;.;.;M;.

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.76

PROVEAN

Uncertain

-3.4

D;D;D;D;D

REVEL

Pathogenic

0.88

Sift

Uncertain

0.0050

D;D;D;D;D

Sift4G

Uncertain

0.021

D;D;D;D;D

Polyphen

1.0

.;.;.;D;.

Vest4

0.96

MVP

0.97

MPC

1.0

ClinPred

0.99

GERP RS

5.4

Varity_R

0.68

gMVP

0.87

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over