14-21031089-G-A

Position:

• chr14-21031089-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_173846.5(TPPP2):​c.251G>A​(p.Gly84Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: TPPP2 NM_173846.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.893

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 (HGNC:):

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1422154).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TPPP2	NM_173846.5	c.251G>A	p.Gly84Glu	missense_variant	3/4	ENST00000321760.11	NP_776245.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TPPP2	ENST00000321760.11	c.251G>A	p.Gly84Glu	missense_variant	3/4	1	NM_173846.5	ENSP00000317595.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461866 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727228

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: 0.0000464

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000936 Hom.: 0

Bravo AF: 0.00000378

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

Aug 12, 2021

The c.251G>A (p.G84E) alteration is located in exon 3 (coding exon 2) of the TPPP2 gene. This alteration results from a G to A substitution at nucleotide position 251, causing the glycine (G) at amino acid position 84 to be replaced by a glutamic acid (E). 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	0.14
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.50
CADD	Benign	13
DANN	Benign	0.95
DEOGEN2	Benign	0.0056	T;.;T;.;T
Eigen	Benign	-0.44
Eigen_PC	Benign	-0.53
FATHMM_MKL	Benign	0.55	D
LIST_S2	Benign	0.77	.;T;T;T;T
M_CAP	Benign	0.0094	T
MetaRNN	Benign	0.14	T;T;T;T;T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	0.92	L;.;L;.;.
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-1.8	N;D;N;D;D
REVEL	Benign	0.037
Sift	Benign	0.081	T;D;T;T;T
Sift4G	Benign	0.39	T;T;T;T;T
Polyphen		0.020	B;.;B;.;.
Vest4		0.25
MutPred		0.48		Gain of solvent accessibility (P = 0.024);Gain of solvent accessibility (P = 0.024);Gain of solvent accessibility (P = 0.024);Gain of solvent accessibility (P = 0.024);.;
MVP		0.014
MPC		0.077
ClinPred		0.17	T
GERP RS		0.65
Varity_R		0.082
gMVP		0.25

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs769599538; hg19: chr14-21499248;