12-10996991-C-T

Variant names:

• chr12-10996991-C-T
• rs137857369
• NM_176889.4:c.885G>A

Variant summary

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

The NM_176889.4(TAS2R20):​c.885G>A​(p.Trp295*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,384 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.815
• 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 2 ACMG points.

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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_176889.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TAS2R20	NM_176889.4	MANE Select	c.885G>A	p.Trp295*	stop_gained	Exon 1 of 1	NP_795370.2	P59543
	PRH1	NM_001291315.2		c.37-23270G>A		intron	N/A	NP_001278244.1
	PRH1	NM_001291314.2		c.-125-23270G>A		intron	N/A	NP_001278243.1	A0A087WV42

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TAS2R20	ENST00000538986.2	TSL:6 MANE Select	c.885G>A	p.Trp295*	stop_gained	Exon 1 of 1	ENSP00000441624.1	P59543
	ENSG00000275778	ENST00000536668.2	TSL:5	n.110-23270G>A		intron	N/A	ENSP00000482961.1	A0A087WZY1
	PRH1	ENST00000703543.1		c.-125-23270G>A		intron	N/A	ENSP00000515364.1	A0A087WYT0

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250862 AF XY: 0.00000738

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461384 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726950

African (AFR) AF: 0.00 AC: 0 AN: 33464

American (AMR) AF: 0.00 AC: 0 AN: 44694

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26108

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86162

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111720

Other (OTH) AF: 0.00 AC: 0 AN: 60384

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Pathogenic	33
DANN	Benign	0.74
Eigen	Benign	-0.10
Eigen_PC	Benign	-0.49
FATHMM_MKL	Benign	0.036	N
PhyloP100		-0.81
Vest4		0.010
GERP RS		1.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=174/26	polymorphism

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

Other links and lift over

dbSNP: rs137857369; hg19: chr12-11149590; COSMIC: COSV67856404;