rs780255825

Positions:

• chr3-122284964-A-C
• chr3-122284964-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_000388.4(CASR):​c.3010A>C​(p.Ser1004Arg) 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. 16/21 in silico tools predict 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. S1004C) 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: 3.35

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 3 ACMG points.

• PM1: In a region_of_interest Disordered (size 20) in uniprot entity CASR_HUMAN there are 6 pathogenic changes around while only 2 benign (75%) 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=0.075570256).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CASR	NM_000388.4	c.3010A>C	p.Ser1004Arg	missense_variant	7/7	ENST00000639785.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CASR	ENST00000639785.2	c.3010A>C	p.Ser1004Arg	missense_variant	7/7	1	NM_000388.4	P1
CASR	ENST00000498619.4	c.3040A>C	p.Ser1014Arg	missense_variant	7/7	1
CASR	ENST00000638421.1	c.3010A>C	p.Ser1004Arg	missense_variant	7/7	5		P1
CASR	ENST00000490131.7	c.2779A>C	p.Ser927Arg	missense_variant	5/5	5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251340 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135854

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 70

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

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

Aug 23, 2020

In summary, this variant has uncertain impact on CASR function. The available evidence is currently insufficient to determine its role 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 tolerated, 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 a CASR-related disease. This variant is present in population databases (rs780255825, ExAC 0.001%). This sequence change replaces serine with arginine at codon 1004 of the CASR protein (p.Ser1004Arg). The serine residue is weakly conserved and there is a moderate physicochemical difference between serine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.057	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	17
DANN	Benign	0.95
DEOGEN2	Benign	0.29	T;T;.;.
Eigen	Benign	-0.75
Eigen_PC	Benign	-0.71
FATHMM_MKL	Benign	0.46	N
LIST_S2	Benign	0.84	.;T;T;T
M_CAP	Benign	0.042	D
MetaRNN	Benign	0.076	T;T;T;T
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	0.0	N;N;.;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-0.44	.;.;N;.
REVEL	Benign	0.21
Sift	Uncertain	0.022	.;.;D;.
Sift4G	Benign	0.064	.;.;T;.
Polyphen		0.0030	B;B;.;.
Vest4		0.18
MutPred		0.13		.;.;Gain of glycosylation at S1013 (P = 0.0442);.;
MVP		0.84
MPC		0.70
ClinPred		0.057	T
GERP RS		0.49
Varity_R		0.083
gMVP		0.18

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: rs780255825; hg19: chr3-122003811;