Genetic Variant CHAT:p.Ser498Leu (chr10-49649618-C-T) – ACMG Classification: Pathogenic (10 pts)

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1PM5PP3_StrongPP5_Moderate

The NM_020549.5(CHAT):c.1493C>T(p.Ser498Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,613,686 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S498P) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

CHAT
NM_020549.5 missense

Scores

Clinical Significance

Likely pathogenic criteria provided, single submitter P:2

Conservation

PhyloP100: 7.57

Publications

5 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: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen
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: Pathogenic. The variant received 10 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_020549.5

PM5

Other missense variant is known to change same aminoacid residue: Variant chr10-49649617-T-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1066458.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.95

PP5

Variant 10-49649618-C-T is Pathogenic according to our data. Variant chr10-49649618-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 17512.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020549.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHAT	NM_020549.5	MANE Select	c.1493C>T	p.Ser498Leu	missense	Exon 10 of 15	NP_065574.4	P28329-1
CHAT	NM_001142933.2		c.1247C>T	p.Ser416Leu	missense	Exon 11 of 16	NP_001136405.2	P28329-2
CHAT	NM_001142929.2		c.1139C>T	p.Ser380Leu	missense	Exon 10 of 15	NP_001136401.2	P28329-3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CHAT	ENST00000337653.7	TSL:1 MANE Select	c.1493C>T	p.Ser498Leu	missense	Exon 10 of 15	ENSP00000337103.2	P28329-1
CHAT	ENST00000395562.2	TSL:1	c.1247C>T	p.Ser416Leu	missense	Exon 11 of 16	ENSP00000378929.2	P28329-2
CHAT	ENST00000339797.5	TSL:1	c.1139C>T	p.Ser380Leu	missense	Exon 10 of 15	ENSP00000343486.1	P28329-3

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152190

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000942

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000160

AC:

AN:

249630

AF XY:

0.0000148

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000546

Gnomad FIN exome

AF:

0.0000924

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461496

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727038

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.000113

AC:

AN:

53040

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1112002

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.465

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152190

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74336

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41450

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.0000942

AC:

AN:

10618

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68042

Other (OTH)

AF:

0.00

AC:

AN:

2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00000462

Hom.:

ExAC

AF:

0.0000247

AC:

ClinVar

ClinVar submissions

Significance:Likely pathogenic

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

Congenital myasthenic syndrome (1)

Familial infantile myasthenia (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.75

BayesDel_addAF

Pathogenic

0.34

BayesDel_noAF

Pathogenic

0.42

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.66

Eigen

Pathogenic

0.75

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.95

M_CAP

Pathogenic

0.32

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

0.95

MutationAssessor

Pathogenic

3.4

PhyloP100

7.6

PrimateAI

Uncertain

0.60

PROVEAN

Uncertain

-3.0

REVEL

Pathogenic

0.89

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0060

Polyphen

1.0

Vest4

0.83

MutPred

0.81

Loss of disorder (P = 0.0114)

MVP

0.97

MPC

0.83

ClinPred

0.97

GERP RS

5.0

Varity_R

0.88

gMVP

0.89

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over