chr8-42839292-C-G

Position:

• chr8-42839292-C-G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_018105.3(THAP1):​c.161G>C​(p.Cys54Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,778 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C54F) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: THAP1 NM_018105.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.14

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 10 ACMG points.

• PM1: In a zinc_finger_region THAP-type (size 80) in uniprot entity THAP1_HUMAN there are 53 pathogenic changes around while only 2 benign (96%) in NM_018105.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
THAP1	NM_018105.3	c.161G>C	p.Cys54Ser	missense_variant	2/3	ENST00000254250.7
THAP1	NM_199003.2	c.72-956G>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
THAP1	ENST00000254250.7	c.161G>C	p.Cys54Ser	missense_variant	2/3	1	NM_018105.3	P1
THAP1	ENST00000345117.2	c.72-956G>C		intron_variant		1
THAP1	ENST00000529779.1	c.161G>C	p.Cys54Ser	missense_variant	2/3	5
THAP1	ENST00000532093.1	n.391G>C		non_coding_transcript_exon_variant	2/2	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461778 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727186

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.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Torsion dystonia 6 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 03, 2016

This sequence change replaces cysteine with serine at codon 54 of the THAP1 protein (p.Cys54Ser). The cysteine residue is highly conserved and there is a moderate physicochemical difference between cysteine and serine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a THAP1-related disease.  However, two different substitutions of this amino acid (p.Cys54Phe and p.Cys54Tyr) have been reported in individuals with dystonia (PMIDs: 21800139, 20865765). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D;.
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	4.2	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-9.4	D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.95
MutPred		0.95		Gain of disorder (P = 0.0188);Gain of disorder (P = 0.0188);
MVP		0.81
MPC		1.6
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.96
gMVP		0.93

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: rs1554599707; hg19: chr8-42694435;