20-41061435-C-T

Variant names:

• chr20-41061435-C-T
• rs1319354641
• NM_003286.4:c.100C>T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_Moderate BS2

The NM_003286.4(TOP1):​c.100C>T​(p.Arg34Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,196 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: TOP1 NM_003286.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.37
• Publications: 0 publications found

Genes affected

TOP1 (HGNC:11986): (DNA topoisomerase I) This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This enzyme catalyzes the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another, thus altering the topology of DNA. This gene is localized to chromosome 20 and has pseudogenes which reside on chromosomes 1 and 22. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Likely_benign. The variant received -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.2421569).
• BS2: High AC in GnomAdExome4 at 6 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003286.4. 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
	TOP1	NM_003286.4	MANE Select	c.100C>T	p.Arg34Trp	missense	Exon 3 of 21	NP_003277.1	P11387

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TOP1	ENST00000361337.3	TSL:1 MANE Select	c.100C>T	p.Arg34Trp	missense	Exon 3 of 21	ENSP00000354522.2	P11387
	TOP1	ENST00000681058.1		n.254C>T		non_coding_transcript_exon	Exon 3 of 20
	TOP1	ENST00000681113.1		n.100C>T		non_coding_transcript_exon	Exon 3 of 23	ENSP00000505788.1	A0A7P0T9R7

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152028 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000404 AC: 1 AN: 247778 AF XY: 0.00000746

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000903

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461168 Hom.: 0 Cov.: 30 AF XY: 0.00000550 AC XY: 4 AN XY: 726860

African (AFR) AF: 0.00 AC: 0 AN: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44642

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26100

East Asian (EAS) AF: 0.00 AC: 0 AN: 39666

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86194

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53364

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111618

Other (OTH) AF: 0.00 AC: 0 AN: 60354

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152028 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74256

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41380

American (AMR) AF: 0.00 AC: 0 AN: 15266

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10590

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67990

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

EpiCase AF: 0.0000546

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
BayesDel_addAF	Benign	-0.083	T
BayesDel_noAF	Benign	-0.36
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Benign	0.29	T
Eigen	Uncertain	0.37
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.96	D
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.24	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.7	L
PhyloP100		2.4
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-1.9	N
REVEL	Benign	0.15
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0050	D
Polyphen		1.0	D
Vest4		0.26
MutPred		0.25		Gain of ubiquitination at K36 (P = 0.0546)
MVP		0.21
MPC		0.81
ClinPred		0.78	D
GERP RS		4.9
Varity_R		0.25
gMVP		0.046
Mutation Taster		=84/16	polymorphism

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: rs1319354641; hg19: chr20-39690075; COSMIC: COSV63693345;