Genetic Variant NM_003286.4:c.1181C>T (chr20-41101226-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_003286.4(TOP1):c.1181C>T(p.Ser394Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,214 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)

Consequence

TOP1
NM_003286.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.23

Variant links:

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]

TOP1 links:

PLCG1-AS1 (HGNC:40450): (PLCG1 antisense RNA 1)

PLCG1-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TOP1	NM_003286.4 link	c.1181C>T	p.Ser394Phe	missense_variant	Exon 13 of 21	ENST00000361337.3	NP_003277.1	P11387Q9BVT2
PLCG1-AS1	NR_109889.1 link	n.774G>A		non_coding_transcript_exon_variant	Exon 5 of 7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TOP1	ENST00000361337.3 link	c.1181C>T	p.Ser394Phe	missense_variant	Exon 13 of 21	1	NM_003286.4	ENSP00000354522.2		P11387

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jun 11, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1181C>T (p.S394F) alteration is located in exon 13 (coding exon 13) of the TOP1 gene. This alteration results from a C to T substitution at nucleotide position 1181, causing the serine (S) at amino acid position 394 to be replaced by a phenylalanine (F). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Benign

-0.50

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.31

Eigen

Benign

0.18

Eigen_PC

Uncertain

0.32

FATHMM_MKL

Uncertain

0.97

LIST_S2

Uncertain

0.97

M_CAP

Benign

0.0046

MetaRNN

Benign

0.21

MetaSVM

Benign

-1.0

MutationAssessor

Benign

0.90

PrimateAI

Uncertain

0.51

PROVEAN

Uncertain

-2.7

REVEL

Benign

0.057

Sift

Uncertain

0.028

Sift4G

Uncertain

0.034

Polyphen

0.51

Vest4

0.23

MutPred

0.44

Loss of disorder (P = 0.0179);

MVP

0.18

MPC

2.1

ClinPred

0.86

GERP RS

4.7

Varity_R

0.39

gMVP

0.44

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.39

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.39

Position offset: 12

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over