3-122254209-G-T

Variant names:

• chr3-122254209-G-T
• rs2074528024
• NM_000388.4:c.20G>T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000388.4(CASR):​c.20G>T​(p.Cys7Phe) 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 1,460,994 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict 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: 0.968

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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 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=0.16138572).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CASR	NM_000388.4	c.20G>T	p.Cys7Phe	missense_variant	Exon 2 of 7	ENST00000639785.2	NP_000379.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CASR	ENST00000639785.2	c.20G>T	p.Cys7Phe	missense_variant	Exon 2 of 7	1	NM_000388.4	ENSP00000491584.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460994 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726790

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

Sep 01, 2021

Labcorp Genetics (formerly Invitae), Labcorp

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	0.049
BayesDel_addAF	Benign	-0.040	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	13
DANN	Benign	0.83
DEOGEN2	Benign	0.33	T;T;.;.
Eigen	Benign	-0.78
Eigen_PC	Benign	-0.65
FATHMM_MKL	Benign	0.73	D
LIST_S2	Benign	0.54	.;T;T;T
M_CAP	Benign	0.042	D
MetaRNN	Benign	0.16	T;T;T;T
MetaSVM	Benign	-0.63	T
MutationAssessor	Benign	1.0	L;L;L;.
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-0.44	.;.;N;N
REVEL	Benign	0.19
Sift	Benign	0.31	.;.;T;T
Sift4G	Benign	0.69	.;.;T;T
Polyphen		0.0	B;B;.;.
Vest4		0.32, 0.30
MutPred		0.55		Loss of glycosylation at S5 (P = 0.0332);Loss of glycosylation at S5 (P = 0.0332);Loss of glycosylation at S5 (P = 0.0332);Loss of glycosylation at S5 (P = 0.0332);
MVP		0.84
MPC		0.93
ClinPred		0.14	T
GERP RS		2.5
Varity_R		0.051
gMVP		0.72

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: rs2074528024; hg19: chr3-121973056;