3-122284197-C-G

Variant names:

• chr3-122284197-C-G
• rs193922433
• NM_000388.4:c.2243C>G
• CASR p.Pro748Arg

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PS3 PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000388.4(CASR):​c.2243C>G​(p.Pro748Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,402 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 Conflicting classifications of pathogenicity (no stars). ClinVar reports functional evidence for this variant: "SCV002557009: Functional studies suggest a detrimental effect on CASR protein function (PMID:19389809, PMID:22798347) and has been shown to alter binding affinity of allosteric modulators (PMID:23372019) (PS3)." and additional evidence is available in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P748L) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 7.90
• Publications: 3 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 16 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV002557009: Functional studies suggest a detrimental effect on CASR protein function (PMID: 19389809, PMID: 22798347) and has been shown to alter binding affinity of allosteric modulators (PMID: 23372019) (PS3).; SCV004028641: The most pronounced variant effect results in impaired localization to plasma membrane and not trafficked to Golgi. PMID:32892159
• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 19 uncertain in NM_000388.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-122284197-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 463923.
• 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, 0.993
• PP5: Variant 3-122284197-C-G is Pathogenic according to our data. Variant chr3-122284197-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 936871.

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.2243C>G	p.Pro748Arg	missense	Exon 7 of 7	NP_000379.3
	CASR	NM_001178065.2		c.2273C>G	p.Pro758Arg	missense	Exon 7 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.2243C>G	p.Pro748Arg	missense	Exon 7 of 7	ENSP00000491584.2	P41180-1
	CASR	ENST00000498619.4	TSL:1	c.2273C>G	p.Pro758Arg	missense	Exon 7 of 7	ENSP00000420194.1	P41180-2
	CASR	ENST00000638421.1	TSL:5	c.2243C>G	p.Pro748Arg	missense	Exon 7 of 7	ENSP00000492190.1	P41180-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461402 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727016

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53270

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111714

Other (OTH) AF: 0.00 AC: 0 AN: 60384

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

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

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		7.9
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-8.3	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Varity_R		0.93
gMVP		0.95
Mutation Taster		=50/50	disease causing (ClinVar)

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

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

Other links and lift over

dbSNP: rs193922433;

hg19: chr3-122003044;