rs10845281

Positions:

• chr12-10997170-T-A
• chr12-10997170-T-C
• chr12-10997170-T-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_176889.4(TAS2R20):​c.706A>T​(p.Ile236Leu) 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 1,461,766 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I236V) has been classified as Likely benign.

• 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: -0.596

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.02627042).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TAS2R20	NM_176889.4	c.706A>T	p.Ile236Leu	missense_variant	1/1	ENST00000538986.2	NP_795370.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TAS2R20	ENST00000538986.2	c.706A>T	p.Ile236Leu	missense_variant	1/1	6	NM_176889.4	ENSP00000441624.1
ENSG00000275778	ENST00000703543.1	c.-125-23449A>T		intron_variant				ENSP00000515364.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251092 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135690

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: 0.0000327

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: 1461766 Hom.: 0 Cov.: 50 AF XY: 0.00000138 AC XY: 1 AN XY: 727174

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.056
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.72
CADD	Benign	0.072
DANN	Benign	0.46
DEOGEN2	Benign	0.0010	T
Eigen	Benign	-2.1
Eigen_PC	Benign	-2.0
FATHMM_MKL	Benign	0.0012	N
M_CAP	Benign	0.00067	T
MetaRNN	Benign	0.026	T
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	-1.5	N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	1.5	N
REVEL	Benign	0.033
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.0	B
Vest4		0.096
MutPred		0.49		Gain of catalytic residue at I236 (P = 3e-04);
MVP		0.11
MPC		0.023
ClinPred		0.071	T
GERP RS		-1.6
Varity_R		0.069
gMVP		0.036

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs10845281; hg19: chr12-11149769;