rs104893694

Variant names:

• chr3-122257347-C-T
• rs104893694
• NM_000388.4:c.452C>T
• CASR p.Thr151Met

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PS3 PM1 PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_000388.4(CASR):​c.452C>T​(p.Thr151Met) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,808 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 Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV005400204: "This variant has moderate functional evidence supporting abnormal protein function. HEK293 cells transfected with this variant displayed maximal responses at lower calcium concentrations (PMID:8813042)."" and additional evidence is available in ClinVar. Synonymous variant affecting the same amino acid position (i.e. T151T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 6.17
• Publications: 14 publications found

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]

CASR Gene-Disease associations (from GenCC):

• autosomal dominant hypocalcemia 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Illumina, ClinGen, Labcorp Genetics (formerly Invitae)
• familial hypocalciuric hypercalcemia 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Illumina, Genomics England PanelApp, ClinGen, Orphanet, Labcorp Genetics (formerly Invitae)
• neonatal severe primary hyperparathyroidism

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen
• autosomal dominant hypocalcemia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• epilepsy, idiopathic generalized, susceptibility to, 8

  Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
• epilepsy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV005400204: "This variant has moderate functional evidence supporting abnormal protein function. HEK293 cells transfected with this variant displayed maximal responses at lower calcium concentrations (PMID: 8813042)."; SCV002069630: Functional study shows p.Thr151Met is a gain-of-function variant, and it results in the activation of CASR at a lower than normal extracellular calcium (PMID: 8878438).; SCV005620495: Assessment of experimental evidence suggests this variant results in abnormal protein function. (PMID: 8878438, 8813042, 35459864); SCV002196350: Experimental studies have shown that this missense change affects CASR function (PMID: 8813042, 8878438).
• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 21 uncertain in NM_000388.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the CASR gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 114 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 3.1237 (above the threshold of 3.09). Trascript score misZ: 4.8257 (above the threshold of 3.09). GenCC associations: The gene is linked to autosomal dominant hypocalcemia, familial hypocalciuric hypercalcemia 1, neonatal severe primary hyperparathyroidism, autosomal dominant hypocalcemia 1, epilepsy, epilepsy, idiopathic generalized, susceptibility to, 8.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.887
• PP5: Variant 3-122257347-C-T is Pathogenic according to our data. Variant chr3-122257347-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 8323.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000388.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CASR	NM_000388.4	MANE Select	c.452C>T	p.Thr151Met	missense	Exon 3 of 7	NP_000379.3
	CASR	NM_001178065.2		c.452C>T	p.Thr151Met	missense	Exon 3 of 7	NP_001171536.2	P41180-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CASR	ENST00000639785.2	TSL:1 MANE Select	c.452C>T	p.Thr151Met	missense	Exon 3 of 7	ENSP00000491584.2	P41180-1
	CASR	ENST00000498619.4	TSL:1	c.452C>T	p.Thr151Met	missense	Exon 3 of 7	ENSP00000420194.1	P41180-2
	CASR	ENST00000638421.1	TSL:5	c.452C>T	p.Thr151Met	missense	Exon 3 of 7	ENSP00000492190.1	P41180-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461808 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727206

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111948

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	Autosomal dominant hypocalcemia 1 (2)
2	-	-	not provided (2)
1	-	-	Familial hypocalciuric hypercalcemia;C3715128:Autosomal dominant hypocalcemia 1 (1)
1	-	-	Familial hypoparathyroidism (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.32	T
Eigen	Uncertain	0.63
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.95	D
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Uncertain	0.13	D
MutationAssessor	Benign	0.64	N
PhyloP100		6.2
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	0.67	N
REVEL	Pathogenic	0.68
Sift	Benign	0.047	D
Sift4G	Benign	0.33	T
Varity_R		0.58
gMVP		0.69
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs104893694;

hg19: chr3-121976194;

COSMIC: COSV56139296;