Genetic Variant TPPP2:p.Thr164Ile (chr14-21032055-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_173846.5(TPPP2):c.491C>T(p.Thr164Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,610 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: 0.0000014 ( 0 hom. )

Consequence

TPPP2
NM_173846.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.98

Variant links:

Genes affected

TPPP2 (HGNC:19293): (tubulin polymerization promoting protein family member 2) Enables tubulin binding activity. Involved in regulation of flagellated sperm motility. Located in cytosol. [provided by Alliance of Genome Resources, Apr 2022]

TPPP2 links:

NDRG2 (HGNC:14460): (NDRG family member 2) This gene is a member of the N-myc downregulated gene family which belongs to the alpha/beta hydrolase superfamily. The protein encoded by this gene is a cytoplasmic protein that may play a role in neurite outgrowth. This gene may be involved in glioblastoma carcinogenesis. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2017]

NDRG2 links:

Genome browser will be placed here

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
TPPP2	NM_173846.5 link	c.491C>T	p.Thr164Ile	missense_variant	Exon 4 of 4	ENST00000321760.11	NP_776245.2	P59282

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TPPP2	ENST00000321760.11 link	c.491C>T	p.Thr164Ile	missense_variant	Exon 4 of 4	1	NM_173846.5	ENSP00000317595.6		P59282

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251174

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135722

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.0000994

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461610

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727050

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.000111

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 07, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.491C>T (p.T164I) alteration is located in exon 4 (coding exon 3) of the TPPP2 gene. This alteration results from a C to T substitution at nucleotide position 491, causing the threonine (T) at amino acid position 164 to be replaced by an isoleucine (I). 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

Uncertain

0.52

BayesDel_addAF

Uncertain

0.14

BayesDel_noAF

Uncertain

-0.040

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.32

T;T

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.72

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.97

.;D

M_CAP

Benign

0.047

MetaRNN

Uncertain

0.67

D;D

MetaSVM

Benign

-0.39

MutationAssessor

Pathogenic

3.2

M;M

PrimateAI

Uncertain

0.49

PROVEAN

Pathogenic

-5.2

D;D

REVEL

Uncertain

0.42

Sift

Uncertain

0.0010

D;D

Sift4G

Uncertain

0.0020

D;D

Polyphen

0.99

D;D

Vest4

0.67

MutPred

0.56

Loss of phosphorylation at T164 (P = 0.0041);Loss of phosphorylation at T164 (P = 0.0041);

MVP

0.22

MPC

0.37

ClinPred

1.0

GERP RS

4.7

Varity_R

0.76

gMVP

0.50

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