20-8132682-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 3P and 3B. PM2 PP2 BP4_Moderate BS1_Supporting

The NM_015192.4(PLCB1):c.31T>G(p.Leu11Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000626 in 1,612,646 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 Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000067 (0 hom.)
• Consequence: PLCB1 NM_015192.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.86

Genes affected

PLCB1 (HGNC:15917): (phospholipase C beta 1) The protein encoded by this gene catalyzes the formation of inositol 1,4,5-trisphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. This reaction uses calcium as a cofactor and plays an important role in the intracellular transduction of many extracellular signals. This gene is activated by two G-protein alpha subunits, alpha-q and alpha-11. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, PLCB1
• BP4: Computational evidence support a benign effect (MetaRNN=0.26308322).
• BS1: Variant frequency is greater than expected in population nfe. gnomad4_exome allele frequency = 0.0000671 (98/1460490) while in subpopulation NFE AF= 0.0000855 (95/1111284). AF 95% confidence interval is 0.0000714. There are 0 homozygotes in gnomad4_exome. There are 37 alleles in male gnomad4_exome subpopulation. Median coverage is 30. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PLCB1	NM_015192.4	c.31T>G	p.Leu11Val	missense_variant	1/32	ENST00000338037.11
PLCB1	NM_182734.3	c.31T>G	p.Leu11Val	missense_variant	1/33

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PLCB1	ENST00000338037.11	c.31T>G	p.Leu11Val	missense_variant	1/32	1	NM_015192.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152156 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000242 AC: 6 AN: 248016 Hom.: 0 AF XY: 0.0000371 AC XY: 5 AN XY: 134762

Gnomad AFR exome AF: 0.0000628

Gnomad AMR exome AF: 0.00

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: 0.0000359

Gnomad OTH exome AF: 0.000166

GnomAD4 exome AF: 0.0000671 AC: 98 AN: 1460490 Hom.: 0 Cov.: 30 AF XY: 0.0000509 AC XY: 37 AN XY: 726622

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: 0.0000855

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152156 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74326

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

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

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Developmental and epileptic encephalopathy, 12 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Aug 31, 2021	This sequence change replaces leucine with valine at codon 11 of the PLCB1 protein (p.Leu11Val). The leucine residue is weakly conserved and there is a small physicochemical difference between leucine and valine. This variant is present in population databases (rs759794686, ExAC 0.01%). This variant has not been reported in the literature in individuals affected with PLCB1-related conditions. 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. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 06, 2017

The p.L11V variant (also known as c.31T>G), located in coding exon 1 of the PLCB1 gene, results from a T to G substitution at nucleotide position 31. The leucine at codon 11 is replaced by valine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.28
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.45
Cadd	Uncertain	23
Dann	Uncertain	0.98
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Uncertain	0.77	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Benign	0.26	T;T;T;T;T
MetaSVM	Benign	-0.74	T
MutationAssessor	Benign	1.8	L;L;.;.;L
MutationTaster	Benign	0.73	D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-1.0	N;N;.;.;N
REVEL	Benign	0.084
Sift	Benign	0.18	T;T;.;.;T
Sift4G	Benign	0.37	T;T;D;D;T
Polyphen		1.0	D;D;.;.;D
Vest4		0.34
MutPred		0.36		Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);
MVP		0.31
MPC		0.18
ClinPred		0.69	D
GERP RS		1.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.20
gMVP		0.30

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

Other links and lift over

dbSNP: rs759794686; hg19: chr20-8113329;