rs977117524

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_020549.5(CHAT):​c.284C>A​(p.Ala95Glu) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000556 in 1,545,648 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A95S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000055 ( 0 hom. )

Consequence

CHAT
NM_020549.5 missense, splice_region

Scores

6
13
Splicing: ADA: 0.7391
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.57

Publications

0 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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.17581332).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CHATNM_020549.5 linkc.284C>A p.Ala95Glu missense_variant, splice_region_variant Exon 1 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.284C>A p.Ala95Glu missense_variant, splice_region_variant Exon 1 of 15 1 NM_020549.5 ENSP00000337103.2 P28329-1

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152110
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.000103
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000143
AC:
2
AN:
140322
AF XY:
0.0000264
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000398
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000553
AC:
77
AN:
1393538
Hom.:
0
Cov.:
35
AF XY:
0.0000538
AC XY:
37
AN XY:
687460
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31588
American (AMR)
AF:
0.00
AC:
0
AN:
35746
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25146
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35826
South Asian (SAS)
AF:
0.0000126
AC:
1
AN:
79174
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
45268
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4072
European-Non Finnish (NFE)
AF:
0.0000686
AC:
74
AN:
1078928
Other (OTH)
AF:
0.0000346
AC:
2
AN:
57790
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
4
7
11
14
18
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.0000592
AC:
9
AN:
152110
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74312
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41428
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5164
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000103
AC:
7
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000176
Hom.:
0
Bravo
AF:
0.0000718

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Familial infantile myasthenia Uncertain:1
Dec 15, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 95 of the CHAT protein (p.Ala95Glu). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with CHAT-related conditions. ClinVar contains an entry for this variant (Variation ID: 498640). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1
Jun 26, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.094
BayesDel_addAF
Uncertain
0.036
T
BayesDel_noAF
Benign
-0.19
CADD
Uncertain
23
DANN
Uncertain
0.99
DEOGEN2
Benign
0.074
T
Eigen
Benign
0.016
Eigen_PC
Benign
0.10
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Benign
0.28
T
M_CAP
Benign
0.074
D
MetaRNN
Benign
0.18
T
MetaSVM
Benign
-0.59
T
MutationAssessor
Benign
0.34
N
PhyloP100
1.6
PrimateAI
Uncertain
0.54
T
PROVEAN
Benign
0.17
N
REVEL
Uncertain
0.34
Sift
Uncertain
0.019
D
Sift4G
Benign
0.34
T
Polyphen
0.74
P
Vest4
0.28
MutPred
0.15
Gain of solvent accessibility (P = 0.0456);
MVP
0.82
MPC
0.29
ClinPred
0.28
T
GERP RS
3.7
PromoterAI
0.25
Neutral
Varity_R
0.26
gMVP
0.20
Mutation Taster
=87/13
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.74
dbscSNV1_RF
Benign
0.61
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

Other links and lift over

dbSNP: rs977117524; hg19: chr10-50822519; API