rs772981786

Positions:

• chr20-8733357-G-A
• chr20-8733357-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_015192.4(PLCB1):​c.2008G>A​(p.Val670Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,766 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: not found (cov: 30)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: PLCB1 NM_015192.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.15

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PLCB1. . Gene score misZ 3.8345 (greater than the threshold 3.09). Trascript score misZ 3.6982 (greater than threshold 3.09). GenCC has associacion of gene with developmental and epileptic encephalopathy, 12, malignant migrating partial seizures of infancy, developmental and epileptic encephalopathy, West syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.22568235).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PLCB1	NM_015192.4	c.2008G>A	p.Val670Ile	missense_variant	19/32	ENST00000338037.11	NP_056007.1
PLCB1	NM_182734.3	c.2008G>A	p.Val670Ile	missense_variant	19/33		NP_877398.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PLCB1	ENST00000338037.11	c.2008G>A	p.Val670Ile	missense_variant	19/32	1	NM_015192.4	ENSP00000338185	P1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251424 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135884

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000821 AC: 12 AN: 1461766 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727188

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome Cov.: 30

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 12 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 27, 2023

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 670 of the PLCB1 protein (p.Val670Ile). This variant is present in population databases (rs772981786, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with PLCB1-related conditions. ClinVar contains an entry for this variant (Variation ID: 567711). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt PLCB1 protein function with a negative predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.39
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Benign	0.25	.;.;.;T;.;T;.;T
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.95	D;D;.;D;D;D;D;D
M_CAP	Benign	0.0096	T
MetaRNN	Benign	0.23	T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	-0.14	.;.;N;N;N;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-0.40	.;.;N;N;N;.;.;.
REVEL	Benign	0.14
Sift	Benign	0.34	.;.;T;T;T;.;.;.
Sift4G	Benign	0.27	.;T;T;T;T;T;T;T
Polyphen		1.0, 0.012	.;.;D;B;D;.;.;.
Vest4		0.25, 0.26, 0.25
MutPred		0.38		.;.;Gain of catalytic residue at V670 (P = 0.1969);Gain of catalytic residue at V670 (P = 0.1969);Gain of catalytic residue at V670 (P = 0.1969);.;.;.;
MVP		0.47
MPC		0.94
ClinPred		0.68	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.13
gMVP		0.46

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs772981786; hg19: chr20-8714004; COSMIC: COSV62071953; COSMIC: COSV62071953;