20-62000709-G-GTCA

Position:

• chr20-62000709-G-GTCA

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PM4_Supporting PP3

The NM_003185.4(TAF4):​c.2496_2498dupTGA​(p.Asp833dup) variant causes a disruptive inframe insertion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TAF4 NM_003185.4 disruptive_inframe_insertion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.70

Genes affected

TAF4 (HGNC:11537): (TATA-box binding protein associated factor 4) Initiation of transcription by RNA polymerase II requires the activities of more than 70 polypeptides. The protein that coordinates these activities is transcription factor IID (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 one of the larger subunits of TFIID that has been shown to potentiate transcriptional activation by retinoic acid, thyroid hormone and vitamin D3 receptors. In addition, this subunit interacts with the transcription factor CREB, which has a glutamine-rich activation domain, and binds to other proteins containing glutamine-rich regions. Aberrant binding to this subunit by proteins with expanded polyglutamine regions has been suggested as one of the pathogenetic mechanisms underlying a group of neurodegenerative disorders referred to as polyglutamine diseases. [provided by RefSeq, Jul 2008]

LOC105372704 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_003185.4. Strenght limited to Supporting due to length of the change: 1aa.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TAF4	NM_003185.4	c.2496_2498dupTGA	p.Asp833dup	disruptive_inframe_insertion	10/15	ENST00000252996.9	NP_003176.2
TAF4	XM_047440429.1	c.1380_1382dupTGA	p.Asp461dup	disruptive_inframe_insertion	11/16		XP_047296385.1
LOC105372704	XM_011529123.2	c.*35_*37dupTGA		downstream_gene_variant			XP_011527425.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TAF4	ENST00000252996.9	c.2496_2498dupTGA	p.Asp833dup	disruptive_inframe_insertion	10/15	1	NM_003185.4	ENSP00000252996.3
TAF4	ENST00000488539.1	c.501_503dupTGA	p.Asp168dup	disruptive_inframe_insertion	5/5	5		ENSP00000476294.1
TAF4	ENST00000436129.2	n.867_869dupTGA		non_coding_transcript_exon_variant	6/11	2
TAF4	ENST00000692470.1	n.372_374dupTGA		non_coding_transcript_exon_variant	4/10			ENSP00000510589.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 27, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In-frame insertion of 1 amino acid in a non-repeat region; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs2055694464; hg19: chr20-60575765;