Genetic Variant COL20A1:p.Arg163Cys (chr20-63306030-C-T) – ACMG Classification: Uncertain_significance (0 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_020882.4(COL20A1):c.487C>T(p.Arg163Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000298 in 1,610,280 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

COL20A1
NM_020882.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.901

Variant links:

Genes affected

COL20A1 (HGNC:14670): (collagen type XX alpha 1 chain) Predicted to be located in endoplasmic reticulum lumen and extracellular region. Predicted to be part of collagen trimer. Predicted to be active in collagen-containing extracellular matrix and extracellular space. [provided by Alliance of Genome Resources, Apr 2022]

COL20A1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.13532451).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL20A1	NM_020882.4 link	c.487C>T	p.Arg163Cys	missense_variant	Exon 5 of 36	ENST00000358894.11	NP_065933.2	Q9P218-1
COL20A1	XM_011528937.2 link	c.487C>T	p.Arg163Cys	missense_variant	Exon 5 of 36		XP_011527239.1
COL20A1	XM_011528938.2 link	c.487C>T	p.Arg163Cys	missense_variant	Exon 5 of 36		XP_011527240.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
COL20A1	ENST00000358894.11 link	c.487C>T	p.Arg163Cys	missense_variant	Exon 5 of 36	1	NM_020882.4	ENSP00000351767.6	Q9P218-1
COL20A1	ENST00000479501.5 link	n.549C>T		non_coding_transcript_exon_variant	Exon 5 of 36	1
COL20A1	ENST00000422202.5 link	c.487C>T	p.Arg163Cys	missense_variant	Exon 4 of 35	5		ENSP00000414753.1	Q9P218-2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152254

Hom.:

Cov.:

show subpopulations

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:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000408

AC:

AN:

245194

Hom.:

AF XY:

0.0000375

AC XY:

AN XY:

133248

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000118

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000112

Gnomad SAS exome

AF:

0.0000333

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000271

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000309

AC:

AN:

1458026

Hom.:

Cov.:

AF XY:

0.0000317

AC XY:

AN XY:

725136

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000902

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.0000466

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000288

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152254

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74384

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000567

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000331

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jan 21, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.487C>T (p.R163C) alteration is located in exon 5 (coding exon 4) of the COL20A1 gene. This alteration results from a C to T substitution at nucleotide position 487, causing the arginine (R) at amino acid position 163 to be replaced by a cysteine (C). 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

-0.28

BayesDel_noAF

Benign

-0.38

CADD

Benign

DANN

Benign

0.95

DEOGEN2

Benign

0.0039

T;.

Eigen

Benign

-0.71

Eigen_PC

Benign

-0.71

FATHMM_MKL

Benign

0.24

LIST_S2

Benign

0.46

T;T

M_CAP

Uncertain

0.13

MetaRNN

Benign

0.14

T;T

MetaSVM

Benign

-0.81

MutationAssessor

Benign

0.0

N;N

PrimateAI

Benign

0.36

PROVEAN

Benign

-0.40

N;N

REVEL

Benign

0.15

Sift

Benign

0.12

T;D

Sift4G

Benign

0.087

T;T

Polyphen

0.14

B;.

Vest4

0.22

MutPred

0.22

Gain of catalytic residue at P162 (P = 0.0074);Gain of catalytic residue at P162 (P = 0.0074);

MVP

0.82

MPC

0.042

ClinPred

0.047

GERP RS

3.9

Varity_R

0.10

gMVP

0.17

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

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