rs1553768082

Positions:

• chr3-122275816-T-A
• chr3-122275816-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The ENST00000639785.2(CASR):​c.1382T>A​(p.Leu461Gln) 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 pathogenic 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. L461P) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CASR ENST00000639785.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.92

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 Likely_pathogenic. Variant got 7 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, 13 uncertain in ENST00000639785.2
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.937

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CASR	NM_000388.4	c.1382T>A	p.Leu461Gln	missense_variant	5/7	ENST00000639785.2	NP_000379.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CASR	ENST00000639785.2	c.1382T>A	p.Leu461Gln	missense_variant	5/7	1	NM_000388.4	ENSP00000491584	P1
CASR	ENST00000498619.4	c.1382T>A	p.Leu461Gln	missense_variant	5/7	1		ENSP00000420194
CASR	ENST00000638421.1	c.1382T>A	p.Leu461Gln	missense_variant	5/7	5		ENSP00000492190	P1
CASR	ENST00000490131.7	c.1378-6297T>A		intron_variant		5		ENSP00000418685

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

CASR-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Nov 02, 2022

The CASR c.1382T>A variant is predicted to result in the amino acid substitution p.Leu461Gln. To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. A different amino acid substitution as this position (p.Leu461Gln) has been reported in two individuals with familial hypocalciuric hypercalcemia (Hannan et al 2012. PubMed ID: 22422767). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 15, 2017

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 missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with CASR-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with glutamine at codon 461 of the CASR protein (p.Leu461Gln). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and glutamine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.81	D;D;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.87	.;D;D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.94	D;D;D
MetaSVM	Uncertain	0.63	D
MutationAssessor	Uncertain	2.7	M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-3.6	.;.;D
REVEL	Pathogenic	0.92
Sift	Benign	0.050	.;.;D
Sift4G	Uncertain	0.020	.;.;D
Polyphen		1.0	D;D;.
Vest4		0.97
MutPred		0.79		Loss of glycosylation at K462 (P = 0.0941);Loss of glycosylation at K462 (P = 0.0941);Loss of glycosylation at K462 (P = 0.0941);
MVP		1.0
MPC		1.6
ClinPred		0.99	D
GERP RS		5.9
Varity_R		0.93
gMVP		0.82

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1553768082; hg19: chr3-121994663;