3-122283896-C-G

Position:

• chr3-122283896-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_000388.4(CASR):​c.1942C>G​(p.Arg648Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,466 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.764

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 5 ACMG points.

• 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, 0.895

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CASR	NM_000388.4	c.1942C>G	p.Arg648Gly	missense_variant	7/7	ENST00000639785.2	NP_000379.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CASR	ENST00000639785.2	c.1942C>G	p.Arg648Gly	missense_variant	7/7	1	NM_000388.4	ENSP00000491584	P1
CASR	ENST00000498619.4	c.1972C>G	p.Arg658Gly	missense_variant	7/7	1		ENSP00000420194
CASR	ENST00000638421.1	c.1942C>G	p.Arg648Gly	missense_variant	7/7	5		ENSP00000492190	P1
CASR	ENST00000490131.7	c.1711C>G	p.Arg571Gly	missense_variant	5/5	5		ENSP00000418685

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251180 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135790

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000993

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461466 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727052

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Labcorp Genetics (formerly Invitae), Labcorp

Apr 06, 2023

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. This variant has not been reported in the literature in individuals affected with CASR-related conditions. This variant is present in population databases (rs104893705, gnomAD 0.01%). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 648 of the CASR protein (p.Arg648Gly). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.67
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.27
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.64	D;D;.;.
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Pathogenic	0.98	.;D;D;D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.89	D;D;D;D
MetaSVM	Uncertain	0.64	D
MutationAssessor	Benign	1.1	L;L;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-2.5	.;.;N;.
REVEL	Pathogenic	0.77
Sift	Uncertain	0.014	.;.;D;.
Sift4G	Benign	0.24	.;.;T;.
Polyphen		1.0	D;D;.;.
Vest4		0.83
MutPred		0.81		.;.;Loss of ubiquitination at K654 (P = 0.0818);.;
MVP		0.88
MPC		1.8
ClinPred		0.86	D
GERP RS		3.9
Varity_R		0.72
gMVP		0.97

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: rs104893705; hg19: chr3-122002743;