2-233729945-G-A

Position:

• chr2-233729945-G-A

Variant summary

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

The NM_019093.4(UGT1A3):​c.819G>A​(p.Met273Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,742 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: UGT1A3 NM_019093.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.21

Genes affected

UGT1A3 (HGNC:12535): (UDP glucuronosyltransferase family 1 member A3) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. Substrates of this enzyme include estrone, 2-hydroxyestrone, and metabolites of benzo alpha-pyrene. [provided by RefSeq, Jul 2008]

UGT1A4 (HGNC:12536): (UDP glucuronosyltransferase family 1 member A4) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. This enzyme has some glucuronidase activity towards bilirubin, although is is more active on amines, steroids, and sapogenins. [provided by RefSeq, Jul 2008]

UGT1A5 (HGNC:12537): (UDP glucuronosyltransferase family 1 member A5) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. [provided by RefSeq, Jul 2008]

UGT1A6 (HGNC:12538): (UDP glucuronosyltransferase family 1 member A6) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. The enzyme encoded by this gene is active on phenolic and planar compounds. Alternative splicing in the unique 5' end of this gene results in two transcript variants. [provided by RefSeq, Jul 2008]

UGT1A10 (HGNC:12531): (UDP glucuronosyltransferase family 1 member A10) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. The enzyme encoded by this gene has glucuronidase activity on mycophenolic acid, coumarins, and quinolines. [provided by RefSeq, Jul 2008]

UGT1A8 (HGNC:12540): (UDP glucuronosyltransferase family 1 member A8) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. The enzyme encoded by this gene has glucuronidase activity with many substrates including coumarins, phenols, anthraquinones, flavones, and some opioids. [provided by RefSeq, Jul 2008]

UGT1A7 (HGNC:12539): (UDP glucuronosyltransferase family 1 member A7) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. The enzyme encoded by this gene has moderate glucuronidase activity with phenols. [provided by RefSeq, Jul 2008]

UGT1A9 (HGNC:12541): (UDP glucuronosyltransferase family 1 member A9) This gene encodes a UDP-glucuronosyltransferase, an enzyme of the glucuronidation pathway that transforms small lipophilic molecules, such as steroids, bilirubin, hormones, and drugs, into water-soluble, excretable metabolites. This gene is part of a complex locus that encodes several UDP-glucuronosyltransferases. The locus includes thirteen unique alternate first exons followed by four common exons. Four of the alternate first exons are considered pseudogenes. Each of the remaining nine 5' exons may be spliced to the four common exons, resulting in nine proteins with different N-termini and identical C-termini. Each first exon encodes the substrate binding site, and is regulated by its own promoter. The enzyme encoded by this gene is active on phenols. [provided by RefSeq, Jul 2008]

UGT1A (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
UGT1A3	NM_019093.4	c.819G>A	p.Met273Ile	missense_variant	1/5	ENST00000482026.6	NP_061966.1
UGT1A4	NM_007120.3	c.867+10258G>A		intron_variant		ENST00000373409.8	NP_009051.1
UGT1A5	NM_019078.2	c.867+16087G>A		intron_variant		ENST00000373414.4	NP_061951.1
UGT1A6	NM_001072.4	c.861+36080G>A		intron_variant		ENST00000305139.11	NP_001063.2
UGT1A10	NM_019075.4	c.856-37089G>A		intron_variant		ENST00000344644.10	NP_061948.1
UGT1A8	NM_019076.5	c.856-37089G>A		intron_variant		ENST00000373450.5	NP_061949.3
UGT1A7	NM_019077.3	c.856-37089G>A		intron_variant		ENST00000373426.4	NP_061950.2
UGT1A9	NM_021027.3	c.856-37089G>A		intron_variant		ENST00000354728.5	NP_066307.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
UGT1A3	ENST00000482026.6	c.819G>A	p.Met273Ile	missense_variant	1/5	1	NM_019093.4	ENSP00000418532.1
UGT1A4	ENST00000373409.8	c.867+10258G>A		intron_variant		1	NM_007120.3	ENSP00000362508.4
UGT1A5	ENST00000373414.4	c.867+16087G>A		intron_variant		1	NM_019078.2	ENSP00000362513.3
UGT1A6	ENST00000305139.11	c.861+36080G>A		intron_variant		1	NM_001072.4	ENSP00000303174.6
UGT1A10	ENST00000344644.10	c.856-37089G>A		intron_variant		1	NM_019075.4	ENSP00000343838.5
UGT1A9	ENST00000354728.5	c.856-37089G>A		intron_variant		1	NM_021027.3	ENSP00000346768.4
UGT1A7	ENST00000373426.4	c.856-37089G>A		intron_variant		1	NM_019077.3	ENSP00000362525.3
UGT1A8	ENST00000373450.5	c.856-37089G>A		intron_variant		1	NM_019076.5	ENSP00000362549.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251288 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135812

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461742 Hom.: 0 Cov.: 108 AF XY: 0.00000413 AC XY: 3 AN XY: 727172

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000165 AC: 2

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

Mar 31, 2024

The c.819G>A (p.M273I) alteration is located in exon 1 (coding exon 1) of the UGT1A3 gene. This alteration results from a G to A substitution at nucleotide position 819, causing the methionine (M) at amino acid position 273 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	Pathogenic	0.61
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.38
CADD	Benign	19
DANN	Uncertain	0.98
DEOGEN2	Benign	0.17	T
Eigen	Benign	-0.17
Eigen_PC	Benign	-0.047
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.83	T
M_CAP	Benign	0.018	T
MetaRNN	Uncertain	0.56	D
MetaSVM	Benign	-0.69	T
MutationAssessor	Benign	1.4	L
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D
PROVEAN	Uncertain	-2.8	D
REVEL	Benign	0.16
Sift	Benign	0.085	T
Sift4G	Benign	0.14	T
Polyphen		0.0010	B
Vest4		0.59
MutPred		0.56		Loss of loop (P = 0.0986);
MVP		0.54
MPC		0.026
ClinPred		0.18	T
GERP RS		4.0
Varity_R		0.42
gMVP		0.29

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: rs752275204; hg19: chr2-234638591;