NM_000388.4:c.1912C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM5PP2PP3_Strong

The NM_000388.4(CASR):​c.1912C>T​(p.Arg638Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000958 in 1,461,704 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. R638H) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

CASR
NM_000388.4 missense

Scores

14
3
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 5.01

Publications

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 26 uncertain in NM_000388.4
PM5
Other missense variant is known to change same aminoacid residue: Variant chr3-122283867-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 265466.
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 neonatal severe primary hyperparathyroidism, autosomal dominant hypocalcemia 1, familial hypocalciuric hypercalcemia 1, epilepsy, autosomal dominant hypocalcemia, epilepsy, idiopathic generalized, susceptibility to, 8.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.966

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CASRNM_000388.4 linkc.1912C>T p.Arg638Cys missense_variant Exon 7 of 7 ENST00000639785.2 NP_000379.3 P41180-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CASRENST00000639785.2 linkc.1912C>T p.Arg638Cys missense_variant Exon 7 of 7 1 NM_000388.4 ENSP00000491584.2 P41180-1
CASRENST00000498619.4 linkc.1942C>T p.Arg648Cys missense_variant Exon 7 of 7 1 ENSP00000420194.1 P41180-2
CASRENST00000638421.1 linkc.1912C>T p.Arg638Cys missense_variant Exon 7 of 7 5 ENSP00000492190.1 P41180-1
CASRENST00000490131.7 linkc.1681C>T p.Arg561Cys missense_variant Exon 5 of 5 5 ENSP00000418685.2 A0A1X7SBX3

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251356
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000464
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1461704
Hom.:
0
Cov.:
33
AF XY:
0.00000825
AC XY:
6
AN XY:
727166
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
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:
39700
South Asian (SAS)
AF:
0.0000812
AC:
7
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53264
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111988
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000283
Hom.:
0
Bravo
AF:
0.00000378
Asia WGS
AF:
0.000289
AC:
1
AN:
3478
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Nephrolithiasis/nephrocalcinosis Uncertain:1
Aug 13, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R638C variant (also known as c.1912C>T), located in coding exon 6 of the CASR gene, results from a C to T substitution at nucleotide position 1912. The arginine at codon 638 is replaced by cysteine, an amino acid with highly dissimilar 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. -

Autosomal dominant hypocalcemia 1;C1809471:Familial hypocalciuric hypercalcemia Uncertain:1
Aug 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 638 of the CASR protein (p.Arg638Cys). This variant is present in population databases (no rsID available, gnomAD 0.005%). 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: 532584). 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. -

Autosomal dominant hypocalcemia 1;C0342637:Familial hypocalciuric hypercalcemia 1;C1832615:Neonatal severe primary hyperparathyroidism;C2752062:Epilepsy, idiopathic generalized, susceptibility to, 8 Uncertain:1
Jun 05, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.15
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.36
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.90
D;D;.;.
Eigen
Pathogenic
0.94
Eigen_PC
Pathogenic
0.87
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.91
.;D;D;D
M_CAP
Pathogenic
0.46
D
MetaRNN
Pathogenic
0.97
D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.1
M;M;.;.
PhyloP100
5.0
PrimateAI
Pathogenic
0.81
D
PROVEAN
Pathogenic
-6.0
.;.;D;.
REVEL
Pathogenic
0.83
Sift
Uncertain
0.011
.;.;D;.
Sift4G
Pathogenic
0.0
.;.;D;.
Polyphen
1.0
D;D;.;.
Vest4
0.47
MutPred
0.84
.;.;Gain of sheet (P = 0.039);.;
MVP
0.97
MPC
1.8
ClinPred
0.94
D
GERP RS
5.9
Varity_R
0.66
gMVP
0.96
Mutation Taster
=20/80
disease causing

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

Other links and lift over

dbSNP: rs1185593894; hg19: chr3-122002713; COSMIC: COSV56138364; API