chr3-122276015-A-T

Position:

• chr3-122276015-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_000388.4(CASR):​c.1581A>T​(p.Lys527Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,872 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 (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CASR NM_000388.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.90

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CASR. . Gene score misZ 3.1237 (greater than the threshold 3.09). Trascript score misZ 4.8257 (greater than threshold 3.09). GenCC has associacion of gene with epilepsy, autosomal dominant hypocalcemia, familial hypocalciuric hypercalcemia 1, epilepsy, idiopathic generalized, susceptibility to, 8, neonatal severe primary hyperparathyroidism, autosomal dominant hypocalcemia 1.
• BP4: Computational evidence support a benign effect (MetaRNN=0.4178658).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CASR	NM_000388.4	c.1581A>T	p.Lys527Asn	missense_variant	5/7	ENST00000639785.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CASR	ENST00000639785.2	c.1581A>T	p.Lys527Asn	missense_variant	5/7	1	NM_000388.4	P1
CASR	ENST00000498619.4	c.1581A>T	p.Lys527Asn	missense_variant	5/7	1
CASR	ENST00000638421.1	c.1581A>T	p.Lys527Asn	missense_variant	5/7	5		P1
CASR	ENST00000490131.7	c.1378-6098A>T		intron_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460872 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726822

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Autosomal dominant hypocalcemia 1;C1809471:Familial hypocalciuric hypercalcemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 17, 2023

This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 527 of the CASR protein (p.Lys527Asn). This variant is not present in population databases (gnomAD no frequency). 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: 532585). 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	0.13
BayesDel_addAF	Uncertain	0.065	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	18
DANN	Uncertain	1.0
DEOGEN2	Benign	0.35	T;T;.
Eigen	Benign	0.050
Eigen_PC	Benign	0.027
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Benign	0.82	.;T;T
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.42	T;T;T
MetaSVM	Uncertain	-0.13	T
MutationAssessor	Benign	1.9	L;L;L
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-1.5	.;.;N
REVEL	Uncertain	0.56
Sift	Benign	0.11	.;.;T
Sift4G	Benign	0.34	.;.;T
Polyphen		1.0	D;D;.
Vest4		0.91
MutPred		0.41		Loss of ubiquitination at K527 (P = 0.0134);Loss of ubiquitination at K527 (P = 0.0134);Loss of ubiquitination at K527 (P = 0.0134);
MVP		0.91
MPC		0.95
ClinPred		0.78	D
GERP RS		1.7
Varity_R		0.43
gMVP		0.80

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

LitVar

Other links and lift over

dbSNP: rs1553768128; hg19: chr3-121994862;