3-122257183-G-T

Position:

• chr3-122257183-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP4

The NM_000388.4(CASR):​c.288G>T​(p.Arg96Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. R96R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.27

Genes affected

CASR (HGNC:1514): (calcium sensing receptor) The protein encoded by this gene is a plasma membrane G protein-coupled receptor that senses small changes in circulating calcium concentration. The encoded protein couples this information to intracellular signaling pathways that modify parathyroid hormone secretion or renal cation handling, and thus this protein plays an essential role in maintaining mineral ion homeostasis. Mutations in this gene are a cause of familial hypocalciuric hypercalcemia, neonatal severe hyperparathyroidism, and autosomal dominant hypocalcemia. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a disulfide_bond (size 41) in uniprot entity CASR_HUMAN there are 19 pathogenic changes around while only 0 benign (100%) in NM_000388.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CASR. . Gene score misZ 3.1237 (greater than the threshold 3.09). Trascript score misZ 4.8257 (greater than threshold 3.09). GenCC has associacion of gene with epilepsy, autosomal dominant hypocalcemia, familial hypocalciuric hypercalcemia 1, epilepsy, idiopathic generalized, susceptibility to, 8, neonatal severe primary hyperparathyroidism, autosomal dominant hypocalcemia 1.
• BP4: Computational evidence support a benign effect (MetaRNN=0.3332926).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CASR	NM_000388.4	c.288G>T	p.Arg96Ser	missense_variant	3/7	ENST00000639785.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CASR	ENST00000639785.2	c.288G>T	p.Arg96Ser	missense_variant	3/7	1	NM_000388.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nephrolithiasis/nephrocalcinosis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 10, 2023

The p.R96S variant (also known as c.288G>T), located in coding exon 2 of the CASR gene, results from a G to T substitution at nucleotide position 288. The arginine at codon 96 is replaced by serine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. 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	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Benign	20
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.53	D;D;.;.
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.11
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.89	.;D;D;D
M_CAP	Benign	0.010	T
MetaRNN	Benign	0.33	T;T;T;T
MetaSVM	Benign	-0.83	T
MutationAssessor	Benign	1.7	L;L;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Benign	-1.6	.;.;N;N
REVEL	Uncertain	0.31
Sift	Benign	0.12	.;.;T;T
Sift4G	Benign	0.17	.;.;T;T
Polyphen		0.028	B;B;.;.
Vest4		0.88, 0.89
MutPred		0.61		Loss of sheet (P = 0.1158);Loss of sheet (P = 0.1158);Loss of sheet (P = 0.1158);Loss of sheet (P = 0.1158);
MVP		0.77
MPC		0.70
ClinPred		0.22	T
GERP RS		2.9
Varity_R		0.74
gMVP		0.83

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: rs375151193; hg19: chr3-121976030; COSMIC: COSV56141138;