X-71366352-C-G

Variant names:

• chrX-71366352-C-G
• rs747589945
• ENST00000373790:c.-23C>G

Variant summary

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

The ENST00000373790(TAF1):​c.-23C>G variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 20)
• Consequence: TAF1 ENST00000373790 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.601

Genes affected

TAF1 (HGNC:11535): (TATA-box binding protein associated factor 1) Initiation of transcription by RNA polymerase II requires the activities of more than 70 polypeptides. The protein that coordinates these activities is the basal transcription factor TFIID, which binds to the core promoter to position the polymerase properly, serves as the scaffold for assembly of the remainder of the transcription complex, and acts as a channel for regulatory signals. TFIID is composed of the TATA-binding protein (TBP) and a group of evolutionarily conserved proteins known as TBP-associated factors or TAFs. TAFs may participate in basal transcription, serve as coactivators, function in promoter recognition or modify general transcription factors (GTFs) to facilitate complex assembly and transcription initiation. This gene encodes the largest subunit of TFIID. This subunit binds to core promoter sequences encompassing the transcription start site. It also binds to activators and other transcriptional regulators, and these interactions affect the rate of transcription initiation. This subunit contains two independent protein kinase domains at the N- and C-terminals, but also possesses acetyltransferase activity and can act as a ubiquitin-activating/conjugating enzyme. Mutations in this gene result in Dystonia 3, torsion, X-linked, a dystonia-parkinsonism disorder. Alternative splicing of this gene results in multiple transcript variants. This gene is part of a complex transcription unit (TAF1/DYT3), wherein some transcript variants share exons with TAF1 as well as additional downstream DYT3 exons. [provided by RefSeq, Oct 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TAF1	NM_004606.5	c.-23C>G		upstream_gene_variant		ENST00000423759.6	NP_004597.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TAF1	ENST00000423759.6	c.-23C>G		upstream_gene_variant		5	NM_004606.5	ENSP00000406549.2

Frequencies

GnomAD3 genomes Cov.: 20

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 20

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Apr 09, 2024

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 glycine, which is neutral and non-polar, at codon 13 of the TAF1 protein (p.Ala13Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TAF1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1708641). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The glycine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Apr 08, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on splicing; In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.093
BayesDel_addAF	Benign	-0.57	T
BayesDel_noAF	Benign	-1.1
CADD	Benign	2.8
DANN	Benign	0.50
DEOGEN2	Benign	0.070	.;T;.
FATHMM_MKL	Benign	0.20	N
LIST_S2	Benign	0.53	T;T;T
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.060	T;T;T
MetaSVM	Benign	-0.94	T
MutationAssessor	Benign	0.0	N;N;N
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-0.040	N;N;N
REVEL	Benign	0.0020
Sift	Benign	0.72	T;T;T
Sift4G	Benign	0.59	T;T;T
Polyphen		0.0	.;B;B
Vest4		0.097
MutPred		0.31		Loss of helix (P = 0.0017);Loss of helix (P = 0.0017);Loss of helix (P = 0.0017);
MVP		0.12
MPC		0.75
ClinPred		0.019	T
GERP RS		-1.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.041
gMVP		0.12

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.60		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.60		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs747589945; hg19: chrX-70586202;