chr12-10986778-G-A

Position:

• chr12-10986778-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_176890.2(TAS2R50):​c.83C>T​(p.Ala28Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000139 in 1,441,336 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 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: TAS2R50 NM_176890.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.917

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]

PRH1-TAS2R14 (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]

TAS2R14 (HGNC:14920): (taste 2 receptor member 14) This gene product belongs to the family of candidate taste receptors that are members of the G-protein-coupled receptor superfamily. These proteins are specifically expressed in the taste receptor cells of the tongue and palate epithelia. They are organized in the genome in clusters and are genetically linked to loci that influence bitter perception in mice and humans. In functional expression studies, they respond to bitter tastants. This gene maps to the taste receptor gene cluster on chromosome 12p13. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.23726693).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TAS2R50	NM_176890.2	c.83C>T	p.Ala28Val	missense_variant	1/1	ENST00000506868.1
PRH1-TAS2R14	NM_001316893.2	c.141-13057C>T		intron_variant
PRH1-PRR4	NR_037918.2	n.478-13057C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TAS2R50	ENST00000506868.1	c.83C>T	p.Ala28Val	missense_variant	1/1		NM_176890.2	P1
	ENST00000703543.1	c.-125-13057C>T		intron_variant				P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000433 AC: 1 AN: 230854 Hom.: 0 AF XY: 0.00000800 AC XY: 1 AN XY: 125010

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000925

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000139 AC: 2 AN: 1441336 Hom.: 0 Cov.: 34 AF XY: 0.00000279 AC XY: 2 AN XY: 716534

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: 0.00000181

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

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

May 27, 2022

The c.83C>T (p.A28V) alteration is located in exon 1 (coding exon 1) of the TAS2R50 gene. This alteration results from a C to T substitution at nucleotide position 83, causing the alanine (A) at amino acid position 28 to be replaced by a valine (V). 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	0.11
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.59
CADD	Benign	2.9
DANN	Uncertain	0.98
DEOGEN2	Benign	0.0063	T
Eigen	Benign	-0.86
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.0052	N
M_CAP	Benign	0.0022	T
MetaRNN	Benign	0.24	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.7	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.26	T
PROVEAN	Benign	-1.5	N
REVEL	Benign	0.095
Sift	Benign	0.35	T
Sift4G	Benign	0.37	T
Polyphen		0.69	P
Vest4		0.12
MutPred		0.56		Gain of sheet (P = 0.0827);
MVP		0.35
MPC		0.029
ClinPred		0.34	T
GERP RS		-1.8
Varity_R		0.079
gMVP		0.11

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: rs745998395; hg19: chr12-11139377;