NM_020549.5:c.789G>A

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_020549.5(CHAT):​c.789G>A​(p.Leu263Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000372 in 1,613,106 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. L263L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0016 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00024 ( 4 hom. )

Consequence

CHAT
NM_020549.5 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 1.14

Publications

1 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.5).
BP6
Variant 10-49625509-G-A is Benign according to our data. Variant chr10-49625509-G-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 461463.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=1.14 with no splicing effect.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00163 (248/152328) while in subpopulation AFR AF = 0.00563 (234/41574). AF 95% confidence interval is 0.00504. There are 0 homozygotes in GnomAd4. There are 132 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 4 AR,AD gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHATNM_020549.5 linkc.789G>A p.Leu263Leu synonymous_variant Exon 6 of 15 ENST00000337653.7 NP_065574.4 P28329-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CHATENST00000337653.7 linkc.789G>A p.Leu263Leu synonymous_variant Exon 6 of 15 1 NM_020549.5 ENSP00000337103.2 P28329-1

Frequencies

GnomAD3 genomes
AF:
0.00159
AC:
242
AN:
152210
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00550
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000654
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:
0.0000441
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000454
AC:
114
AN:
251184
AF XY:
0.000361
show subpopulations
Gnomad AFR exome
AF:
0.00554
Gnomad AMR exome
AF:
0.000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000241
AC:
352
AN:
1460778
Hom.:
4
Cov.:
32
AF XY:
0.000220
AC XY:
160
AN XY:
726706
show subpopulations
African (AFR)
AF:
0.00700
AC:
234
AN:
33438
American (AMR)
AF:
0.000626
AC:
28
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86200
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.000817
AC:
4
AN:
4896
European-Non Finnish (NFE)
AF:
0.0000441
AC:
49
AN:
1111994
Other (OTH)
AF:
0.000581
AC:
35
AN:
60284
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.465
Heterozygous variant carriers
0
19
37
56
74
93
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
20
40
60
80
100
<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:
0.00163
AC:
248
AN:
152328
Hom.:
0
Cov.:
33
AF XY:
0.00177
AC XY:
132
AN XY:
74486
show subpopulations
African (AFR)
AF:
0.00563
AC:
234
AN:
41574
American (AMR)
AF:
0.000653
AC:
10
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68028
Other (OTH)
AF:
0.000473
AC:
1
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
Heterozygous variant carriers
0
14
28
43
57
71
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
4
8
12
16
20
<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:
0.000671
Hom.:
0
Bravo
AF:
0.00172
Asia WGS
AF:
0.00115
AC:
4
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:2
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Sep 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

CHAT: BP4, BP7 -

not specified Benign:1
Mar 01, 2017
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Familial infantile myasthenia Benign:1
Jan 30, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.50
CADD
Benign
4.6
DANN
Benign
0.66
PhyloP100
1.1
Mutation Taster
=100/0
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs114090981; hg19: chr10-50833555; API