3-122262273-A-T

Position:

• chr3-122262273-A-T

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.1238A>T​(p.His413Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,886 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, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.32

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, 0.848

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CASR	NM_000388.4	c.1238A>T	p.His413Leu	missense_variant	4/7	ENST00000639785.2	NP_000379.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CASR	ENST00000639785.2	c.1238A>T	p.His413Leu	missense_variant	4/7	1	NM_000388.4	ENSP00000491584.2
CASR	ENST00000498619.4	c.1238A>T	p.His413Leu	missense_variant	4/7	1		ENSP00000420194.1
CASR	ENST00000638421.1	c.1238A>T	p.His413Leu	missense_variant	4/7	5		ENSP00000492190.1
CASR	ENST00000490131.7	c.1238A>T	p.His413Leu	missense_variant	3/5	5		ENSP00000418685.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461886 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Nephrolithiasis/nephrocalcinosis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 26, 2024

The p.H413L variant (also known as c.1238A>T), located in coding exon 3 of the CASR gene, results from an A to T substitution at nucleotide position 1238. The histidine at codon 413 is replaced by leucine, an amino acid with similar properties. Limited functional analysis suggests no significant impact (Zhang C et al. J. Biol. Chem., 2014 Feb;289:5296-309). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 16, 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. Experimental studies have shown that this missense change does not substantially affect CASR function (PMID: 24394414). 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. ClinVar contains an entry for this variant (Variation ID: 532598). 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 histidine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 413 of the CASR protein (p.His413Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.45
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Uncertain	23
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.70	D;D;.;.
Eigen	Uncertain	0.66
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.89	.;D;D;D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.85	D;D;D;D
MetaSVM	Uncertain	0.23	D
MutationAssessor	Benign	1.2	L;L;L;.
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-4.2	.;.;D;D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.012	.;.;D;D
Sift4G	Benign	0.25	.;.;T;T
Polyphen		1.0	D;D;.;.
Vest4		0.83, 0.83
MutPred		0.51		Gain of catalytic residue at H413 (P = 0.0173);Gain of catalytic residue at H413 (P = 0.0173);Gain of catalytic residue at H413 (P = 0.0173);Gain of catalytic residue at H413 (P = 0.0173);
MVP		0.98
MPC		1.7
ClinPred		0.97	D
GERP RS		5.9
Varity_R		0.72
gMVP		0.87

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: rs1553766896; hg19: chr3-121981120;