10-49662688-G-A

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BP6

The NM_020549.5(CHAT):c.1883G>A(p.Arg628Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000696 in 1,614,188 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R628W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00073 ( 0 hom. )

Consequence

CHAT
NM_020549.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 8.15

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

congenital myasthenic syndrome 6
Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
presynaptic congenital myasthenic syndrome
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

CHAT links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 9 uncertain in NM_020549.5

BP6

Variant 10-49662688-G-A is Benign according to our data. Variant chr10-49662688-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 194422.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHAT	NM_020549.5 link	c.1883G>A	p.Arg628Gln	missense_variant	Exon 14 of 15	ENST00000337653.7	NP_065574.4	P28329-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHAT	ENST00000337653.7 link	c.1883G>A	p.Arg628Gln	missense_variant	Exon 14 of 15	1	NM_020549.5	ENSP00000337103.2		P28329-1

Frequencies

GnomAD3 genomes

AF:

0.000388

AC:

AN:

152186

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000193

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000691

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000338

AC:

AN:

251482

AF XY:

0.000243

show subpopulations

Gnomad AFR exome

AF:

0.000185

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.000298

Gnomad EAS exome

AF:

0.000109

Gnomad FIN exome

AF:

0.0000924

Gnomad NFE exome

AF:

0.000633

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000729

AC:

1065

AN:

1461884

Hom.:

Cov.:

AF XY:

0.000681

AC XY:

495

AN XY:

727246

show subpopulations

African (AFR)

AF:

0.0000597

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.000115

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000926

AC:

1030

AN:

1112002

Other (OTH)

AF:

0.000397

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.477

Heterozygous variant carriers

125

188

250

313

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

138

184

230

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000387

AC:

AN:

152304

Hom.:

Cov.:

AF XY:

0.000416

AC XY:

AN XY:

74494

show subpopulations

African (AFR)

AF:

0.000192

AC:

AN:

41566

American (AMR)

AF:

0.000131

AC:

AN:

15300

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5176

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.0000941

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000691

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.504

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000620

Hom.:

Bravo

AF:

0.000329

TwinsUK

AF:

0.00162

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.000349

AC:

ExAC

AF:

0.000338

AC:

EpiCase

AF:

0.000545

EpiControl

AF:

0.000533

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Sep 10, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Observed with a second CHAT pathogenic variant in 4 members of a family affected with arthrogryposis multiplex congenita; however segregation and pedigree data were not provided (PMID: 33820833); This variant is associated with the following publications: (PMID: 26080897, 33820833) -

Jan 28, 2015

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Familial infantile myasthenia

Uncertain:1Benign:1

Dec 12, 2023

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Nov 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Benign

-0.0016

BayesDel_noAF

Pathogenic

0.20

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.57

.;.;.;D;.;.

Eigen

Uncertain

0.53

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.90

.;.;D;D;D;D

M_CAP

Uncertain

0.23

MetaRNN

Uncertain

0.58

D;D;D;D;D;D

MetaSVM

Pathogenic

0.92

MutationAssessor

Uncertain

2.1

.;.;.;M;.;.

PhyloP100

8.1

PrimateAI

Uncertain

0.50

PROVEAN

Uncertain

-2.5

N;N;N;N;N;.

REVEL

Pathogenic

0.76

Sift

Benign

0.074

T;T;T;D;D;.

Sift4G

Benign

0.093

T;T;T;T;T;.

Polyphen

1.0

.;.;.;D;.;.

Vest4

0.59

MVP

0.97

MPC

0.59

ClinPred

0.85

GERP RS

4.7

Varity_R

0.61

gMVP

0.84

Mutation Taster

=46/54

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over