20-8132484-G-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_015192.4(PLCB1):c.-168G>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00142 in 364,084 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 0.0011 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0017 (0 hom.)
• Consequence: PLCB1 NM_015192.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.282

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 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=-0.78).
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00106 (161/151910) while in subpopulation NFE AF= 0.00187 (127/67874). AF 95% confidence interval is 0.00161. There are 0 homozygotes in gnomad4. There are 67 alleles in male gnomad4 subpopulation. Median coverage is 32. 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.-168G>A		5_prime_UTR_variant	1/32	ENST00000338037.11
PLCB1	NM_182734.3	c.-168G>A		5_prime_UTR_variant	1/33

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PLCB1	ENST00000338037.11	c.-168G>A		5_prime_UTR_variant	1/32	1	NM_015192.4	P1

Frequencies

GnomAD3 genomes AF: 0.00107 AC: 162 AN: 151802 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000169

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00138

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: 0.00189

Gnomad OTH AF: 0.00288

GnomAD4 exome AF: 0.00168 AC: 357 AN: 212174 Hom.: 0 Cov.: 3 AF XY: 0.00172 AC XY: 188 AN XY: 109462

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00178

Gnomad4 ASJ exome AF: 0.000145

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.000133

Gnomad4 NFE exome AF: 0.00225

Gnomad4 OTH exome AF: 0.00280

GnomAD4 genome AF: 0.00106 AC: 161 AN: 151910 Hom.: 0 Cov.: 32 AF XY: 0.000902 AC XY: 67 AN XY: 74258

Gnomad4 AFR AF: 0.000169

Gnomad4 AMR AF: 0.00138

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00187

Gnomad4 OTH AF: 0.00285

Alfa AF: 0.00104 Hom.: 0

Bravo AF: 0.00131

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

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
Cadd	Benign	11
Dann	Benign	0.95
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

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: rs548635433; hg19: chr20-8113131;