7-141973045-C-T

Position:

• chr7-141973045-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Moderate BS2

The NM_176817.5(TAS2R38):​c.645G>A​(p.Met215Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000363 in 1,461,882 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. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.000036 (0 hom.)
• Consequence: TAS2R38 NM_176817.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.05

Genes affected

TAS2R38 (HGNC:9584): (taste 2 receptor member 38) This gene encodes a seven-transmembrane G protein-coupled receptor that controls the ability to taste glucosinolates, a family of bitter-tasting compounds found in plants of the Brassica sp. Synthetic compounds phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) have been identified as ligands for this receptor and have been used to test the genetic diversity of this gene. Although several allelic forms of this gene have been identified worldwide, there are two predominant common forms (taster and non-taster) found outside of Africa. These alleles differ at three nucleotide positions resulting in amino acid changes in the protein (A49P, A262V, and V296I) with the amino acid combination PAV identifying the taster variant (and AVI identifying the non-taster variant). [provided by RefSeq, Oct 2009]

MGAM (HGNC:7043): (maltase-glucoamylase) This gene encodes maltase-glucoamylase, which is a brush border membrane enzyme that plays a role in the final steps of digestion of starch. The protein has two catalytic sites identical to those of sucrase-isomaltase, but the proteins are only 59% homologous. Both are members of glycosyl hydrolase family 31, which has a variety of substrate specificities. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.17074823).
• BS2: High AC in GnomAdExome4 at 53 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TAS2R38	NM_176817.5	c.645G>A	p.Met215Ile	missense_variant	1/1	ENST00000547270.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TAS2R38	ENST00000547270.1	c.645G>A	p.Met215Ile	missense_variant	1/1		NM_176817.5	P1
MGAM	ENST00000465654.5	c.-3+27048C>T		intron_variant		3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251238 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135782

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000363 AC: 53 AN: 1461882 Hom.: 0 Cov.: 63 AF XY: 0.0000330 AC XY: 24 AN XY: 727244

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: 0.0000187

Gnomad4 NFE exome AF: 0.0000450

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.00000378

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000259 AC: 1

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

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

Jul 13, 2022

The c.645G>A (p.M215I) alteration is located in exon 1 (coding exon 1) of the TAS2R38 gene. This alteration results from a G to A substitution at nucleotide position 645, causing the methionine (M) at amino acid position 215 to be replaced by an isoleucine (I). 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	0.18
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.72
CADD	Benign	12
DANN	Benign	0.80
DEOGEN2	Benign	0.0046	T
Eigen	Benign	-0.91
Eigen_PC	Benign	-0.91
FATHMM_MKL	Benign	0.087	N
LIST_S2	Uncertain	0.86	D
M_CAP	Benign	0.0072	T
MetaRNN	Benign	0.17	T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	1.4	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.28	T
PROVEAN	Benign	-0.070	N
REVEL	Benign	0.021
Sift	Benign	0.094	T
Sift4G	Benign	0.46	T
Polyphen		0.0090	B
Vest4		0.089
MutPred		0.63		Gain of catalytic residue at L220 (P = 0.0441);
MVP		0.092
MPC		0.23
ClinPred		0.054	T
GERP RS		0.82
Varity_R		0.12
gMVP		0.094

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: rs782642723; hg19: chr7-141672845;