rs1554804021

Positions:

• chr10-49627663-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_020549.5(CHAT):​c.989T>C​(p.Phe330Ser) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: CHAT NM_020549.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.73

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.823

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHAT	NM_020549.5	c.989T>C	p.Phe330Ser	missense_variant	7/15	ENST00000337653.7	NP_065574.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHAT	ENST00000337653.7	c.989T>C	p.Phe330Ser	missense_variant	7/15	1	NM_020549.5	ENSP00000337103	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

CHAT-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Jan 12, 2023

The CHAT c.989T>C variant is predicted to result in the amino acid substitution p.Phe330Ser. This variant was reported in the compound heterozygous state an individual with multisystem features consistent with a CHAT-related disorder (Table S2. Klee et al 2021. PubMed ID: 33144682). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Although we suspect that this variant may be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Familial infantile myasthenia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Apr 14, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.43
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.56	.;.;.;D;.
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.85	.;.;D;D;D
M_CAP	Benign	0.064	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Benign	1.4	.;.;.;L;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-3.6	D;D;D;D;D
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0080	D;D;D;T;T
Sift4G	Benign	0.18	T;T;T;T;T
Polyphen		0.99	.;.;.;D;.
Vest4		0.89
MutPred		0.59		.;.;.;Gain of disorder (P = 0.0064);.;
MVP		0.95
MPC		0.75
ClinPred		0.99	D
GERP RS		5.7
Varity_R		0.74
gMVP		0.54

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

LitVar

Other links and lift over

dbSNP: rs1554804021; hg19: chr10-50835709;