NM_001899.3:c.93A>G

Variant names:

• chr20-23688877-T-C
• rs3188293
• NM_001899.3:c.93A>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_001899.3(CST4):​c.93A>G​(p.Pro31Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,872 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 Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CST4 NM_001899.3 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -1.95
• Publications: 1 publications found

Genes affected

CST4 (HGNC:2476): (cystatin S) 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 type 2 salivary cysteine peptidase inhibitor. The protein is an S-type cystatin, based on its high level of expression in saliva, tears and seminal plasma. The specific role in these fluids is unclear but antibacterial and antiviral activity is present, consistent with a protective function. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-1.06).
• BP6: Variant 20-23688877-T-C is Benign according to our data. Variant chr20-23688877-T-C is described in ClinVar as Likely_benign. ClinVar VariationId is 2652243.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-1.95 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001899.3. 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
	CST4	NM_001899.3	MANE Select	c.93A>G	p.Pro31Pro	synonymous	Exon 1 of 3	NP_001890.1	P01036

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CST4	ENST00000217423.4	TSL:1 MANE Select	c.93A>G	p.Pro31Pro	synonymous	Exon 1 of 3	ENSP00000217423.3	P01036

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152138 Hom.: 0 Cov.: 33

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

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461872 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000657 AC: 1 AN: 152254 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74438

African (AFR) AF: 0.00 AC: 0 AN: 41566

American (AMR) AF: 0.00 AC: 0 AN: 15300

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5158

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 290

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67994

Other (OTH) AF: 0.00 AC: 0 AN: 2110

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, single submitter

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-1.1
CADD	Benign	0.29
DANN	Benign	0.24
PhyloP100		-1.9
PromoterAI		0.014	Neutral

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: rs3188293; hg19: chr20-23669514;