rs1553769162

chr3-122284599-A-G

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.2645A>G(p.Lys882Arg) variant causes a missense change involving the alteration of a 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K882E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.24

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 hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000388.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, CASR
• BP4: Computational evidence support a benign effect (MetaRNN=0.3370331).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CASR	NM_000388.4	c.2645A>G	p.Lys882Arg	missense_variant	7/7	ENST00000639785.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CASR	ENST00000639785.2	c.2645A>G	p.Lys882Arg	missense_variant	7/7	1	NM_000388.4	P1
CASR	ENST00000498619.4	c.2675A>G	p.Lys892Arg	missense_variant	7/7	1
CASR	ENST00000638421.1	c.2645A>G	p.Lys882Arg	missense_variant	7/7	5		P1
CASR	ENST00000490131.7	c.2414A>G	p.Lys805Arg	missense_variant	5/5	5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 71

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal dominant hypocalcemia 1;C1809471:Familial hypocalciuric hypercalcemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 25, 2022

ClinVar contains an entry for this variant (Variation ID: 463933). This variant has not been reported in the literature in individuals affected with CASR-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 882 of the CASR protein (p.Lys882Arg). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25"). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.092
BayesDel_addAF	Uncertain	0.075	D
BayesDel_noAF	Benign	-0.13
Cadd	Benign	23
Dann	Uncertain	0.99
DEOGEN2	Benign	0.38	T;T;.;.
Eigen	Benign	0.084
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.040	D
MetaRNN	Benign	0.34	T;T;T;T
MetaSVM	Uncertain	-0.13	T
MutationAssessor	Benign	1.8	L;L;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.76	T
Polyphen		0.015	B;B;.;.
Vest4		0.18
MutPred		0.40		.;.;Loss of methylation at K892 (P = 0.0126);.;
MVP		0.94
MPC		0.54
ClinPred		0.83	D
GERP RS		5.9
Varity_R		0.16
gMVP		0.59

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: rs1553769162; hg19: chr3-122003446;