3-122262362-C-A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_000388.4(CASR):​c.1327C>A​(p.Leu443Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000149 in 1,613,870 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. L443F) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

CASR
NM_000388.4 missense

Scores

4
15

Clinical Significance

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

Conservation

PhyloP100: 3.94

Publications

3 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_benign. The variant received -1 ACMG points.

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.
BP4
Computational evidence support a benign effect (MetaRNN=0.24236414).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CASRNM_000388.4 linkc.1327C>A p.Leu443Ile missense_variant Exon 4 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.1327C>A p.Leu443Ile missense_variant Exon 4 of 7 1 NM_000388.4 ENSP00000491584.2 P41180-1
CASRENST00000498619.4 linkc.1327C>A p.Leu443Ile missense_variant Exon 4 of 7 1 ENSP00000420194.1 P41180-2
CASRENST00000638421.1 linkc.1327C>A p.Leu443Ile missense_variant Exon 4 of 7 5 ENSP00000492190.1 P41180-1
CASRENST00000490131.7 linkc.1327C>A p.Leu443Ile missense_variant Exon 3 of 5 5 ENSP00000418685.2 A0A1X7SBX3

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152200
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000399
AC:
1
AN:
250360
AF XY:
0.00
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:
0.00
Gnomad NFE exome
AF:
0.00000885
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000137
AC:
20
AN:
1461670
Hom.:
0
Cov.:
33
AF XY:
0.0000138
AC XY:
10
AN XY:
727138
show subpopulations
⚠️ 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:
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:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53222
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000180
AC:
20
AN:
1111988
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000001), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.393
Heterozygous variant carriers
0
1
2
4
5
6
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
AF:
0.0000263
AC:
4
AN:
152200
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74370
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.538
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000387
Hom.:
0
Bravo
AF:
0.0000151
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.00
AC:
0
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Sep 11, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: CASR c.1327C>A (p.Leu443Ile) results in a conservative amino acid change located in the Receptor, ligand binding region (IPR001828) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 250360 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1327C>A has been reported in the literature in an individual affected with ectopic mineralization (Saeidian_2022). This report does not provide unequivocal conclusions about association of the variant with Familial Hypocalciuric Hypercalcemia. Co-occurrences with other pathogenic variant(s) have been reported (ABCC6 exon23-29del; ABCC6 c.3490C>T, p.R1164*), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 34906475). ClinVar contains an entry for this variant (Variation ID: 410336). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Nephrolithiasis/nephrocalcinosis Uncertain:1
Nov 03, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.L443I variant (also known as c.1327C>A), located in coding exon 3 of the CASR gene, results from a C to A substitution at nucleotide position 1327. The leucine at codon 443 is replaced by isoleucine, an amino acid with highly similar properties. This alteration was identified in an individual from an international cohort of 478 pseudoxanthoma elasticum patients with ectopic mineralization; this individual is also noted to be compound heterozygous for alterations in ABCC6 (Saeidian AH et al. Genet Med, 2022 Jan;24:75-86). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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
Oct 03, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 443 of the CASR protein (p.Leu443Ile). This variant is present in population databases (rs267599574, gnomAD 0.0009%). 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: 410336). 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 tolerated. 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
Benign
0.14
BayesDel_addAF
Uncertain
0.092
D
BayesDel_noAF
Benign
-0.11
CADD
Benign
20
DANN
Benign
0.96
DEOGEN2
Benign
0.35
T;T;.;.
Eigen
Benign
-0.067
Eigen_PC
Benign
0.15
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.85
.;D;T;T
M_CAP
Benign
0.029
D
MetaRNN
Benign
0.24
T;T;T;T
MetaSVM
Benign
-0.54
T
MutationAssessor
Benign
1.1
L;L;L;.
PhyloP100
3.9
PrimateAI
Uncertain
0.70
T
PROVEAN
Benign
-0.45
.;.;N;N
REVEL
Uncertain
0.35
Sift
Benign
0.41
.;.;T;T
Sift4G
Benign
0.66
.;.;T;T
Polyphen
0.014
B;B;.;.
Vest4
0.47, 0.32
MVP
0.88
MPC
0.77
ClinPred
0.31
T
GERP RS
5.7
Varity_R
0.47
gMVP
0.28
Mutation Taster
=65/35
polymorphism

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: rs267599574; hg19: chr3-121981209; COSMIC: COSV56141674; COSMIC: COSV56141674; API