NM_018319.4:c.148G>T

Variant names:

• chr14-89963262-G-T
• rs781564388
• NM_018319.4:c.148G>T

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_018319.4(TDP1):​c.148G>T​(p.Glu50*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TDP1 NM_018319.4 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.84
• Publications: 0 publications found

Genes affected

TDP1 (HGNC:18884): (tyrosyl-DNA phosphodiesterase 1) The protein encoded by this gene is involved in repairing stalled topoisomerase I-DNA complexes by catalyzing the hydrolysis of the phosphodiester bond between the tyrosine residue of topoisomerase I and the 3-prime phosphate of DNA. This protein may also remove glycolate from single-stranded DNA containing 3-prime phosphoglycolate, suggesting a role in repair of free-radical mediated DNA double-strand breaks. This gene is a member of the phospholipase D family and contains two PLD phosphodiesterase domains. Mutations in this gene are associated with the disease spinocerebellar ataxia with axonal neuropathy (SCAN1). [provided by RefSeq, Aug 2016]

TDP1 Gene-Disease associations (from GenCC):

• spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 1

  Inheritance: AR Classification: STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• male infertility with azoospermia or oligozoospermia due to single gene mutation

  Inheritance: AR Classification: NO_KNOWN Submitted by: King Faisal Specialist Hospital and Research Center

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TDP1	NM_018319.4	c.148G>T	p.Glu50*	stop_gained	Exon 3 of 17	ENST00000335725.9	NP_060789.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TDP1	ENST00000335725.9	c.148G>T	p.Glu50*	stop_gained	Exon 3 of 17	1	NM_018319.4	ENSP00000337353.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000312 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		6.8
Vest4		0.45
GERP RS		5.5
PromoterAI		0.010	Neutral
Mutation Taster		=2/198	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs781564388; hg19: chr14-90429606;