3-122261645-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PP2 PP3_Strong

The NM_000388.4(CASR):c.610T>C(p.Phe204Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,888 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F204I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.02

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.

• PP2: Missense variant where missense usually causes diseases, CASR
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.947

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CASR	NM_000388.4	c.610T>C	p.Phe204Leu	missense_variant	4/7	ENST00000639785.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CASR	ENST00000639785.2	c.610T>C	p.Phe204Leu	missense_variant	4/7	1	NM_000388.4	P1
CASR	ENST00000498619.4	c.610T>C	p.Phe204Leu	missense_variant	4/7	1
CASR	ENST00000638421.1	c.610T>C	p.Phe204Leu	missense_variant	4/7	5		P1
CASR	ENST00000490131.7	c.610T>C	p.Phe204Leu	missense_variant	3/5	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461888 Hom.: 0 Cov.: 33 AF XY: 0.00000688 AC XY: 5 AN XY: 727244

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: 0.00000809

Gnomad4 OTH exome AF: 0.0000166

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

Dec 13, 2019

The p.F204L variant (also known as c.610T>C), located in coding exon 3 of the CASR gene, results from a T to C substitution at nucleotide position 610. The phenylalanine at codon 204 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, 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

Invitae

Dec 19, 2023

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 204 of the CASR protein (p.Phe204Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CASR-related conditions. ClinVar contains an entry for this variant (Variation ID: 572669). 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	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
Cadd	Pathogenic	26
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.81	D;D;.;.
Eigen	Pathogenic	0.69
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Uncertain	0.16	D
MetaRNN	Pathogenic	0.95	D;D;D;D
MetaSVM	Uncertain	0.38	D
MutationAssessor	Uncertain	2.1	M;M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.88	D
Polyphen		1.0	D;D;.;.
Vest4		0.94, 0.93
MutPred		0.83		Gain of catalytic residue at F204 (P = 0.0124);Gain of catalytic residue at F204 (P = 0.0124);Gain of catalytic residue at F204 (P = 0.0124);Gain of catalytic residue at F204 (P = 0.0124);
MVP		0.96
MPC		1.7
ClinPred		0.99	D
GERP RS		5.8
Varity_R		0.86
gMVP		0.91

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: rs1060499700; hg19: chr3-121980492;