rs1555299812

Variant names:

• chr13-102627149-A-G
• rs1555299812
• NM_001330588.2:c.922A>G

Variant summary

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

The NM_001330588.2(TPP2):​c.922A>G​(p.Thr308Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000414 in 1,448,218 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: TPP2 NM_001330588.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.82

Genes affected

TPP2 (HGNC:12016): (tripeptidyl peptidase 2) This gene encodes a mammalian peptidase that, at neutral pH, removes tripeptides from the N terminus of longer peptides. The protein has a specialized function that is essential for some MHC class I antigen presentation. The protein is a high molecular mass serine exopeptidase; the amino acid sequence surrounding the serine residue at the active site is similar to the peptidases of the subtilisin class rather than the trypsin class. [provided by RefSeq, Jul 2008]

ACMG classification

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
TPP2	NM_001330588.2	c.922A>G	p.Thr308Ala	missense_variant	Exon 7 of 30	ENST00000376052.5	NP_001317517.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPP2	ENST00000376052.5	c.922A>G	p.Thr308Ala	missense_variant	Exon 7 of 30	5	NM_001330588.2	ENSP00000365220.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000414 AC: 6 AN: 1448218 Hom.: 0 Cov.: 30 AF XY: 0.00000417 AC XY: 3 AN XY: 720138

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000452

Gnomad4 OTH exome AF: 0.0000167

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Evans syndrome, immunodeficiency, and premature immunosenescence associated with tripeptidyl-peptidase II deficiency Uncertain:1

Nov 02, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with alanine at codon 308 of the TPP2 protein (p.Thr308Ala). The threonine residue is highly conserved and there is a small physicochemical difference between threonine and alanine. This variant has not been reported in the literature in individuals with TPP2-related disease. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.30
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.61	D;.
Eigen	Uncertain	0.21
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Benign	0.077	D
MetaRNN	Uncertain	0.66	D;D
MetaSVM	Uncertain	-0.094	T
MutationAssessor	Benign	1.0	L;.
PrimateAI	Pathogenic	0.80	T
PROVEAN	Uncertain	-3.3	D;D
REVEL	Pathogenic	0.71
Sift	Benign	0.070	T;T
Sift4G	Benign	0.071	T;T
Polyphen		0.31	B;.
Vest4		0.71
MutPred		0.62		Gain of catalytic residue at T306 (P = 0.0011);Gain of catalytic residue at T306 (P = 0.0011);
MVP		0.72
MPC		0.82
ClinPred		0.94	D
GERP RS		5.4
Varity_R		0.23
gMVP		0.87

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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

Other links and lift over

dbSNP: rs1555299812; hg19: chr13-103279499;