chr14-89984610-T-C

Variant names:

• chr14-89984610-T-C
• rs1555387536
• NM_018319.4:c.979T>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_018319.4(TDP1):​c.979T>C​(p.Leu327Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,818 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TDP1 NM_018319.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.49
• 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: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.56).
• BP7: Synonymous conserved (PhyloP=1.49 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_018319.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TDP1	NM_018319.4	MANE Select	c.979T>C	p.Leu327Leu	synonymous	Exon 9 of 17	NP_060789.2
	TDP1	NM_001008744.2		c.979T>C	p.Leu327Leu	synonymous	Exon 8 of 16	NP_001008744.1
	TDP1	NM_001330205.2		c.979T>C	p.Leu327Leu	synonymous	Exon 8 of 15	NP_001317134.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TDP1	ENST00000335725.9	TSL:1 MANE Select	c.979T>C	p.Leu327Leu	synonymous	Exon 9 of 17	ENSP00000337353.4
	TDP1	ENST00000393454.6	TSL:1	c.979T>C	p.Leu327Leu	synonymous	Exon 8 of 16	ENSP00000377099.2
	TDP1	ENST00000393452.7	TSL:1	c.979T>C	p.Leu327Leu	synonymous	Exon 9 of 18	ENSP00000377098.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461818 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727220

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53388

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111970

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.56
CADD	Benign	5.6
DANN	Benign	0.37
PhyloP100		1.5

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

Other links and lift over

dbSNP: rs1555387536; hg19: chr14-90450954; COSMIC: COSV59642661; COSMIC: COSV59642661;