3-122284950-A-G

Position:

• chr3-122284950-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_000388.4(CASR):​c.2996A>G​(p.Glu999Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,198 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.67

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.

• PM1: In a topological_domain Cytoplasmic (size 215) in uniprot entity CASR_HUMAN there are 14 pathogenic changes around while only 2 benign (88%) 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CASR	NM_000388.4	c.2996A>G	p.Glu999Gly	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.2996A>G	p.Glu999Gly	missense_variant	7/7	1	NM_000388.4	ENSP00000491584	P1
CASR	ENST00000498619.4	c.3026A>G	p.Glu1009Gly	missense_variant	7/7	1		ENSP00000420194
CASR	ENST00000638421.1	c.2996A>G	p.Glu999Gly	missense_variant	7/7	5		ENSP00000492190	P1
CASR	ENST00000490131.7	c.2765A>G	p.Glu922Gly	missense_variant	5/5	5		ENSP00000418685

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152198 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 70

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152198 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74352

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

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

Jul 08, 2023

ClinVar contains an entry for this variant (Variation ID: 946792). This sequence change replaces glutamic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 999 of the CASR protein (p.Glu999Gly). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with CASR-related conditions. 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.096
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T;T;.;.
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	.;D;D;D
M_CAP	Uncertain	0.25	D
MetaRNN	Uncertain	0.60	D;D;D;D
MetaSVM	Uncertain	0.66	D
MutationAssessor	Benign	1.8	L;L;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-1.1	.;.;N;.
REVEL	Uncertain	0.53
Sift	Uncertain	0.0020	.;.;D;.
Sift4G	Uncertain	0.0050	.;.;D;.
Polyphen		1.0	D;D;.;.
Vest4		0.37
MutPred		0.20		.;.;Loss of helix (P = 0.0068);.;
MVP		0.96
MPC		1.7
ClinPred		0.95	D
GERP RS		5.8
Varity_R		0.31
gMVP		0.61

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: rs201052958; hg19: chr3-122003797;