Genetic Variant CST8:p.Lys97Gln (chr20-23493015-A-C) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_005492.4(CST8):c.289A>C(p.Lys97Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,826 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

CST8
NM_005492.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.86

Variant links:

Genes affected

CST8 (HGNC:2480): (cystatin 8) The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions. The cystatin locus on chromosome 20 contains the majority of the type 2 cystatin genes and pseudogenes. This gene is located in the cystatin locus and encodes a protein similar to type 2 cystatins. The encoded protein exhibits highly tissue-specific expression in the reproductive tract, suggesting implicit roles in reproduction. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2013]

CST8 links:

ENSG00000260202 (HGNC:):

ENSG00000260202 links:

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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
CST8	NM_005492.4 link	c.289A>C	p.Lys97Gln	missense_variant	Exon 3 of 4	ENST00000246012.2	NP_005483.1	O60676A0A384MDQ4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
CST8	ENST00000246012.2 link	c.289A>C	p.Lys97Gln	missense_variant	Exon 3 of 4	1	NM_005492.4	ENSP00000246012.1	O60676
CST8	ENST00000449810.5 link	c.289A>C	p.Lys97Gln	missense_variant	Exon 3 of 4	3		ENSP00000399144.1	A2A2N0
ENSG00000260202	ENST00000619495.1 link	n.439-11252T>G		intron_variant	Intron 1 of 1	4

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152168

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000290

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

GnomAD3 exomes

AF:

0.0000278

AC:

AN:

251426

Hom.:

AF XY:

0.0000294

AC XY:

AN XY:

135884

show subpopulations

Gnomad AFR exome

AF:

0.000185

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461540

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727090

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000854

AC:

AN:

152286

Hom.:

Cov.:

AF XY:

0.000107

AC XY:

AN XY:

74470

show subpopulations

Gnomad4 AFR

AF:

0.000289

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000579

Hom.:

Bravo

AF:

0.0000642

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

May 31, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.289A>C (p.K97Q) alteration is located in exon 3 (coding exon 2) of the CST8 gene. This alteration results from a A to C substitution at nucleotide position 289, causing the lysine (K) at amino acid position 97 to be replaced by a glutamine (Q). 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

Pathogenic

0.56

BayesDel_addAF

Benign

-0.086

BayesDel_noAF

Benign

-0.13

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.37

.;T

Eigen

Uncertain

0.38

Eigen_PC

Benign

0.18

FATHMM_MKL

Benign

0.36

LIST_S2

Benign

0.50

T;T

M_CAP

Benign

0.013

MetaRNN

Uncertain

0.43

T;T

MetaSVM

Benign

-0.56

MutationAssessor

Pathogenic

3.6

.;H

PrimateAI

Uncertain

0.51

PROVEAN

Uncertain

-3.8

D;D

REVEL

Uncertain

0.31

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

.;D

Vest4

0.66

MVP

0.57

MPC

0.0038

ClinPred

0.98

GERP RS

4.4

Varity_R

0.92

gMVP

0.70

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