3-122284347-C-T
Variant summary
Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PP2PP3_StrongPP5_Very_Strong
The NM_000388.4(CASR):c.2393C>T(p.Pro798Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,184 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P798S) has been classified as Uncertain significance.
Frequency
Consequence
NM_000388.4 missense
Scores
Clinical Significance
Conservation
Publications
- autosomal dominant hypocalcemia 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Illumina, ClinGen, Labcorp Genetics (formerly Invitae)
- familial hypocalciuric hypercalcemia 1Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Illumina, Orphanet, Genomics England PanelApp
- neonatal severe primary hyperparathyroidismInheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, ClinGen, Labcorp Genetics (formerly Invitae)
- autosomal dominant hypocalcemiaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- epilepsy, idiopathic generalized, susceptibility to, 8Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
- epilepsyInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Pathogenic. The variant received 17 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| CASR | NM_000388.4 | c.2393C>T | p.Pro798Leu | missense_variant | Exon 7 of 7 | ENST00000639785.2 | NP_000379.3 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| CASR | ENST00000639785.2 | c.2393C>T | p.Pro798Leu | missense_variant | Exon 7 of 7 | 1 | NM_000388.4 | ENSP00000491584.2 | ||
| CASR | ENST00000498619.4 | c.2423C>T | p.Pro808Leu | missense_variant | Exon 7 of 7 | 1 | ENSP00000420194.1 | |||
| CASR | ENST00000638421.1 | c.2393C>T | p.Pro798Leu | missense_variant | Exon 7 of 7 | 5 | ENSP00000492190.1 | |||
| CASR | ENST00000490131.7 | c.2162C>T | p.Pro721Leu | missense_variant | Exon 5 of 5 | 5 | ENSP00000418685.2 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152184Hom.: 0 Cov.: 33 show subpopulations
GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0AN: 1461772Hom.: 0 Cov.: 70 AF XY: 0.00 AC XY: 0AN XY: 727194
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152184Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74332 show subpopulations ⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:2
In some published literature, this variant is referred to as c.2423C>T p.(Pro808Leu). This variant has been identified in multiple unrelated individuals with clinical features of hypocalciuric hypercalcemia. At least one other missense variant at this codon is considered to be pathogenic or likely pathogenic, suggesting this variant may also cause disease. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). Computational tools predict that this variant is damaging.
Autosomal dominant hypocalcemia 1;C1809471:Familial hypocalciuric hypercalcemia Pathogenic:1
This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 798 of the CASR protein (p.Pro798Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with familial hypocalciuric hypercalcemia (PMID: 15963484, 22422767, 31672324; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 410346). 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. This variant disrupts the p.Pro798 amino acid residue in CASR. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15963484, 19389809). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.
Familial hypocalciuric hypercalcemia Pathogenic:1
Variant summary: CASR c.2393C>T (p.Pro798Leu) results in a non-conservative amino acid change located in the GPCR family 3, C-terminal domain (IPR017978) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant was absent in 251304 control chromosomes. c.2393C>T has been observed in multiple individuals affected with Familial Hypocalciuric Hypercalcemia and/or autosomal dominant Familial Hyperparathyroidism (e.g. Hannan_2012, Hureaux_2019, Gorvin_2019, Mariathasan_2020, Mazarico-Altisent_2023). These data indicate that the variant is very likely to be associated with disease. A different variant affecting the same codon has been classified as pathogenic by our lab (c.2392C>A, p.Pro798Thr), supporting the critical relevance of codon 798 to CASR protein function. The following publications have been ascertained in the context of this evaluation (PMID: 31189130, 22422767, 31672324, 32430905, 37810884). ClinVar contains an entry for this variant (Variation ID: 410346). Based on the evidence outlined above, the variant was classified as pathogenic.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at