10-49610786-A-G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_003055.3(SLC18A3):​c.46A>G​(p.Lys16Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000014 in 1,423,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. 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. K16N) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 35)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SLC18A3
NM_003055.3 missense

Scores

1
3
15

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.52

Publications

0 publications found
Variant links:
Genes affected
SLC18A3 (HGNC:10936): (solute carrier family 18 member A3) This gene is a member of the vesicular amine transporter family. The encoded transmembrane protein transports acetylcholine into secretory vesicles for release into the extracellular space. Acetylcholine transport utilizes a proton gradient established by a vacuolar ATPase. This gene is located within the first intron of the choline acetyltransferase gene. [provided by RefSeq, Jul 2008]
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: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.16524848).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SLC18A3NM_003055.3 linkc.46A>G p.Lys16Glu missense_variant Exon 1 of 1 ENST00000374115.5 NP_003046.2 Q16572
CHATNM_020984.4 linkc.-69+1587A>G intron_variant Intron 1 of 14 NP_066264.4 P28329-3D3DX95

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SLC18A3ENST00000374115.5 linkc.46A>G p.Lys16Glu missense_variant Exon 1 of 1 6 NM_003055.3 ENSP00000363229.3 Q16572
CHATENST00000339797.5 linkc.-69+1587A>G intron_variant Intron 1 of 14 1 ENSP00000343486.1 P28329-3

Frequencies

GnomAD3 genomes
Cov.:
35
GnomAD2 exomes
AF:
0.0000105
AC:
2
AN:
189688
AF XY:
0.00000970
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000756
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000140
AC:
2
AN:
1423882
Hom.:
0
Cov.:
79
AF XY:
0.00000142
AC XY:
1
AN XY:
705696
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32450
American (AMR)
AF:
0.0000538
AC:
2
AN:
37146
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24738
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38380
South Asian (SAS)
AF:
0.00
AC:
0
AN:
81604
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50374
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5648
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1094698
Other (OTH)
AF:
0.00
AC:
0
AN:
58844
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
Cov.:
35
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.00000837
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Uncertain:1
Oct 26, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces lysine with glutamic acid at codon 16 of the SLC18A3 protein (p.Lys16Glu). The lysine residue is highly conserved and there is a small physicochemical difference between lysine and glutamic acid. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has not been reported in the literature in individuals affected with SLC18A3-related conditions. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Benign
-0.15
T
BayesDel_noAF
Benign
-0.46
CADD
Benign
20
DANN
Benign
0.91
DEOGEN2
Benign
0.17
T
Eigen
Benign
-0.38
Eigen_PC
Benign
-0.20
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.55
T
M_CAP
Uncertain
0.11
D
MetaRNN
Benign
0.17
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Uncertain
2.1
M
PhyloP100
3.5
PrimateAI
Pathogenic
0.86
D
PROVEAN
Benign
-0.58
N
REVEL
Benign
0.093
Sift
Benign
0.66
T
Sift4G
Benign
0.74
T
Polyphen
0.24
B
Vest4
0.093
MutPred
0.25
Loss of MoRF binding (P = 0.0073);
MVP
0.28
ClinPred
0.11
T
GERP RS
4.1
PromoterAI
-0.013
Neutral
Varity_R
0.14
gMVP
0.43
Mutation Taster
=78/22
polymorphism

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

Other links and lift over

dbSNP: rs753971264; hg19: chr10-50818832; API