8-68022107-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Moderate BP6_Moderate BP7

The NM_024870.4(PREX2):c.408C>T(p.Leu136=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000359 in 1,561,656 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 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000038 (0 hom.)
• Consequence: PREX2 NM_024870.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.0190

Genes affected

PREX2 (HGNC:22950): (phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 2) The protein encoded by this gene belongs to the phosphatidylinositol 3,4,5-trisphosphate (PIP3)-dependent Rac exchanger (PREX) family, which are Dbl-type guanine-nucleotide exchange factors for Rac family small G proteins. Structural domains of this protein include the catalytic diffuse B-cell lymphoma homology and pleckstrin homology (DHPH) domain, two disheveled, EGL-10, and pleckstrin homology (DEP) domains, two PDZ domains, and a C-terminal inositol polyphosphate-4 phosphatase (IP4P) domain that is found in one of the isoforms. This protein facilitates the exchange of GDP for GTP on Rac1, allowing the GTP-bound Rac1 to activate downstream effectors. Studies also show that the pleckstrin homology domain of this protein interacts with the phosphatase and tensin homolog (PTEN) gene product to inhibit PTEN phosphatase activity, thus activating the phosphoinositide-3 kinase (PI3K) signaling pathway. Conversely, the PTEN gene product has also been shown to inhibit the GEF activity of this protein. This gene plays a role in insulin-signaling pathways, and either mutations or overexpression of this gene have been observed in some cancers. [provided by RefSeq, Apr 2016]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.4).
• BP6: Variant 8-68022107-C-T is Benign according to our data. Variant chr8-68022107-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 3049219.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=0.019 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PREX2	NM_024870.4	c.408C>T	p.Leu136=	synonymous_variant	4/40	ENST00000288368.5
PREX2	NM_025170.6	c.408C>T	p.Leu136=	synonymous_variant	4/24
PREX2	XM_047422267.1	c.273C>T	p.Leu91=	synonymous_variant	4/40
PREX2	XM_047422268.1	c.408C>T	p.Leu136=	synonymous_variant	4/28

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PREX2	ENST00000288368.5	c.408C>T	p.Leu136=	synonymous_variant	4/40	1	NM_024870.4	P1
PREX2	ENST00000529398.5	n.435C>T		non_coding_transcript_exon_variant	4/24	1
PREX2	ENST00000517617.1	n.119C>T		non_coding_transcript_exon_variant	2/24	2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152054 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000199 AC: 5 AN: 250810 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135594

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000868

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000376 AC: 53 AN: 1409602 Hom.: 0 Cov.: 24 AF XY: 0.0000341 AC XY: 24 AN XY: 704598

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000672

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: 0.0000470

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152054 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74268

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

PREX2-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 06, 2019

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.40
Cadd	Benign	6.9
Dann	Benign	0.81

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs953865013; hg19: chr8-68934342;