12-10997112-C-G

Variant names:

• chr12-10997112-C-G
• rs10845279
• NM_176889.4:c.764G>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_176889.4(TAS2R20):​c.764G>C​(p.Arg255Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,718 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TAS2R20 NM_176889.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.885
• Publications: 0 publications found

Genes affected

TAS2R20 (HGNC:19109): (taste 2 receptor member 20) This gene encodes a member of the taste receptor two family of class C G-protein coupled receptors. Receptors of this family have a short extracellular N-terminus, seven transmembrane helices, three extracellular loops and three intracellular loops, and an intracellular C-terminus. Members of this family are expressed in a subset of taste receptor cells, where they function in bitter taste reception, as well as in non-gustatory cells including those of the brain, reproductive organs, respiratory system, and gastrointestinal system. This gene maps to the taste receptor gene cluster on chromosome 12p13. [provided by RefSeq, Jul 2016]

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]

PRR4 (HGNC:18020): (proline rich 4) This gene encodes a member of the proline-rich protein family that lacks a conserved repetitive domain. This protein may play a role in protective functions in the eye. Alternative splicing result in multiple transcript variants. Read-through transcription also exists between this gene and the upstream PRH1 (proline-rich protein HaeIII subfamily 1) gene. [provided by RefSeq, Feb 2011]

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

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.07039288).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TAS2R20	NM_176889.4	c.764G>C	p.Arg255Pro	missense_variant	Exon 1 of 1	ENST00000538986.2	NP_795370.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TAS2R20	ENST00000538986.2	c.764G>C	p.Arg255Pro	missense_variant	Exon 1 of 1	6	NM_176889.4	ENSP00000441624.1
ENSG00000275778	ENST00000536668.2	n.110-23391G>C		intron_variant	Intron 3 of 9	5		ENSP00000482961.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461718 Hom.: 0 Cov.: 48 AF XY: 0.00 AC XY: 0 AN XY: 727154

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44692

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86236

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111920

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.72
CADD	Benign	0.020
DANN	Benign	0.57
DEOGEN2	Benign	0.0027	T
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.0070	N
M_CAP	Benign	0.0010	T
MetaRNN	Benign	0.070	T
MetaSVM	Benign	-0.89	T
MutationAssessor	Benign	-1.1	N
PhyloP100		-0.89
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-1.1	N
REVEL	Benign	0.020
Sift	Benign	0.15	T
Sift4G	Benign	0.35	T
Polyphen		0.0	B
Vest4		0.057
MutPred		0.48		Gain of catalytic residue at R255 (P = 0);
MVP		0.099
MPC		0.027
ClinPred		0.049	T
GERP RS		-5.3
Varity_R		0.14
gMVP		0.093
Mutation Taster		=100/0	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

Other links and lift over

dbSNP: rs10845279; hg19: chr12-11149711;