20-23603533-T-A

Position:

• chr20-23603533-T-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001008693.3(CST9):​c.457A>T​(p.Ile153Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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: not found (cov: 33)
• Consequence: CST9 NM_001008693.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.34

Genes affected

CST9 (HGNC:13261): (cystatin 9) 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, where they appear to provide protective functions. 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 secreted protein that may play a role in hematopoietic differentiation or inflammation. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.042685598).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CST9	NM_001008693.3	c.457A>T	p.Ile153Phe	missense_variant	2/2	ENST00000376971.4	NP_001008693.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CST9	ENST00000376971.4	c.457A>T	p.Ile153Phe	missense_variant	2/2	1	NM_001008693.3	ENSP00000366170.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 03, 2023

The c.457A>T (p.I153F) alteration is located in exon 2 (coding exon 2) of the CST9 gene. This alteration results from a A to T substitution at nucleotide position 457, causing the isoleucine (I) at amino acid position 153 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	0.082
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.72
CADD	Benign	0.13
DANN	Benign	0.93
DEOGEN2	Benign	0.0073	T
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.0069	N
LIST_S2	Benign	0.48	T
M_CAP	Benign	0.00096	T
MetaRNN	Benign	0.043	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-0.11	N
REVEL	Benign	0.027
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.0	B
Vest4		0.10
MutPred		0.16		Loss of methylation at K151 (P = 0.0787);
MVP		0.040
MPC		0.089
ClinPred		0.071	T
GERP RS		-4.5
Varity_R		0.10
gMVP		0.26

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr20-23584170;