rs1131691345

Positions:

• chr8-42838099-G-A
• chr8-42838099-G-C

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_018105.3(THAP1):​c.505C>T​(p.Arg169*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: THAP1 NM_018105.3 stop_gained
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 3.31

Genes affected

THAP1 (HGNC:20856): (THAP domain containing 1) The protein encoded by this gene contains a THAP domain, a conserved DNA-binding domain. This protein colocalizes with the apoptosis response protein PAWR/PAR-4 in promyelocytic leukemia (PML) nuclear bodies, and functions as a proapoptotic factor that links PAWR to PML nuclear bodies. Alternatively spliced transcript variants encoding distinct isoforms have been observed. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 6 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-42838099-G-A is Pathogenic according to our data. Variant chr8-42838099-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 429366.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
THAP1	NM_018105.3	c.505C>T	p.Arg169*	stop_gained	3/3	ENST00000254250.7	NP_060575.1
THAP1	NM_199003.2	c.*147C>T		3_prime_UTR_variant	2/2		NP_945354.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
THAP1	ENST00000254250.7	c.505C>T	p.Arg169*	stop_gained	3/3	1	NM_018105.3	ENSP00000254250.3
THAP1	ENST00000345117	c.*147C>T		3_prime_UTR_variant	2/2	1		ENSP00000344966.2
THAP1	ENST00000529779.1	c.*46C>T		downstream_gene_variant		5		ENSP00000433912.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461884 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727242

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Torsion dystonia 6 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 29, 2018

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Other truncations (p.Arg172Lysfs*7 and p.Asp191Thrfs*9) that lie downstream of this variant have been reported in individuals affected with dystonia (PMID: 21520283, 21847143). This variant has been observed to segregate with clinical features of dystonia in a family (Invitae). ClinVar contains an entry for this variant (Variation ID: 429366). This variant is not present in population databases (ExAC no frequency). This sequence change results in a premature translational stop signal in the THAP1 gene (p.Arg169*). While this is not anticipated to result in nonsense mediated decay, it is expected to delete the last 45 amino acids of the THAP1 protein. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jan 27, 2020

Nonsense variant in the C-terminus predicted to result in protein truncation, as the last 45 amino acids are lost, and other loss-of-function variants have been reported downstream in the Human Gene Mutation Database (Stenson et al., 2014); Not observed in large population cohorts (Lek et al., 2016); Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.89	D
Vest4		0.87
GERP RS		3.7

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: rs1131691345; hg19: chr8-42693242; COSMIC: COSV54273817; COSMIC: COSV54273817;