12-10986021-A-C

Position:

• chr12-10986021-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_176890.2(TAS2R50):​c.840T>G​(p.Ile280Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,154 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: TAS2R50 NM_176890.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.955

Genes affected

TAS2R50 (HGNC:18882): (taste 2 receptor member 50) TAS2R50 belongs to the large TAS2R receptor family. TAS2Rs are expressed on the surface of taste receptor cells and mediate the perception of bitterness through a G protein-coupled second messenger pathway (Conte et al., 2002 [PubMed 12584440]). See also TAS2R10 (MIM 604791).[supplied by OMIM, Mar 2008]

ENSG00000275778 (HGNC:):

PRH1 (HGNC:9366): (proline rich protein HaeIII subfamily 1) This gene encodes a member of the heterogeneous family of proline-rich salivary glycoproteins. The encoded preproprotein undergoes proteolytic processing to generate one or more mature isoforms before secretion from the parotid and submandibular/sublingual glands. Multiple distinct alleles of this locus including the parotid isoelectric-focusing variant slow (PIF-s), the parotid acidic protein (Pa), and the double band slow (Db-s) isoforms have been characterized. The reference genome encodes the Db-s allele. Certain alleles of this gene are associated with susceptibility to dental caries. This gene is located in a cluster of closely related salivary proline-rich proteins on chromosome 12. Co-transcription of this gene with adjacent genes has been observed. Alternate splicing of this gene results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Oct 2015]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TAS2R50	NM_176890.2	c.840T>G	p.Ile280Met	missense_variant	1/1	ENST00000506868.1	NP_795371.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TAS2R50	ENST00000506868.1	c.840T>G	p.Ile280Met	missense_variant	1/1	6	NM_176890.2	ENSP00000424040.1
ENSG00000275778	ENST00000703543.1	c.-125-12300T>G		intron_variant				ENSP00000515364.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152154 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 29

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152154 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74346

Gnomad4 AFR AF: 0.0000242

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 10, 2024

The c.840T>G (p.I280M) alteration is located in exon 1 (coding exon 1) of the TAS2R50 gene. This alteration results from a T to G substitution at nucleotide position 840, causing the isoleucine (I) at amino acid position 280 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
CADD	Benign	15
DANN	Uncertain	0.99
DEOGEN2	Benign	0.049	T
Eigen	Benign	-0.0040
Eigen_PC	Benign	-0.34
FATHMM_MKL	Benign	0.11	N
M_CAP	Benign	0.0016	T
MetaRNN	Uncertain	0.58	D
MetaSVM	Benign	-1.1	T
MutationAssessor	Pathogenic	4.0	H
PrimateAI	Benign	0.46	T
PROVEAN	Uncertain	-2.8	D
REVEL	Benign	0.10
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.36
MutPred		0.73		Loss of ubiquitination at K285 (P = 0.0744);
MVP		0.42
MPC		0.13
ClinPred		0.99	D
GERP RS		2.2
Varity_R		0.69
gMVP		0.21

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1281058338; hg19: chr12-11138620;