chr2-233772281-C-T

Variant names:

• chr2-233772281-C-T
• rs143033456
• NM_007120.3:c.1327C>T

Variant summary

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

The NM_007120.3(UGT1A4):​c.1327C>T​(p.Arg443Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00013 in 1,614,084 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000085 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00013 (1 hom.)
• Consequence: UGT1A4 NM_007120.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:8
• Conservation: PhyloP100: 3.03

Genes affected

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]

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]

UGT1A1 (HGNC:12530): (UDP glucuronosyltransferase family 1 member A1) 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 preferred substrate of this enzyme is bilirubin, although it also has moderate activity with simple phenols, flavones, and C18 steroids. Mutations in this gene result in Crigler-Najjar syndromes types I and II and in Gilbert syndrome. [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:12529):

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 rank	MANE	Protein	UniProt
UGT1A4	NM_007120.3	c.1327C>T	p.Arg443Cys	missense_variant	Exon 5 of 5	ENST00000373409.8	NP_009051.1
UGT1A5	NM_019078.2	c.1327C>T	p.Arg443Cys	missense_variant	Exon 5 of 5	ENST00000373414.4	NP_061951.1
UGT1A3	NM_019093.4	c.1327C>T	p.Arg443Cys	missense_variant	Exon 5 of 5	ENST00000482026.6	NP_061966.1
UGT1A1	NM_000463.3	c.1324C>T	p.Arg442Cys	missense_variant	Exon 5 of 5	ENST00000305208.10	NP_000454.1
UGT1A6	NM_001072.4	c.1321C>T	p.Arg441Cys	missense_variant	Exon 5 of 5	ENST00000305139.11	NP_001063.2
UGT1A10	NM_019075.4	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	ENST00000344644.10	NP_061948.1
UGT1A8	NM_019076.5	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	ENST00000373450.5	NP_061949.3
UGT1A7	NM_019077.3	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	ENST00000373426.4	NP_061950.2
UGT1A9	NM_021027.3	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	ENST00000354728.5	NP_066307.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
UGT1A4	ENST00000373409.8	c.1327C>T	p.Arg443Cys	missense_variant	Exon 5 of 5	1	NM_007120.3	ENSP00000362508.4
UGT1A5	ENST00000373414.4	c.1327C>T	p.Arg443Cys	missense_variant	Exon 5 of 5	1	NM_019078.2	ENSP00000362513.3
UGT1A3	ENST00000482026.6	c.1327C>T	p.Arg443Cys	missense_variant	Exon 5 of 5	1	NM_019093.4	ENSP00000418532.1
UGT1A1	ENST00000305208.10	c.1324C>T	p.Arg442Cys	missense_variant	Exon 5 of 5	1	NM_000463.3	ENSP00000304845.5
UGT1A6	ENST00000305139.11	c.1321C>T	p.Arg441Cys	missense_variant	Exon 5 of 5	1	NM_001072.4	ENSP00000303174.6
UGT1A10	ENST00000344644.10	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	1	NM_019075.4	ENSP00000343838.5
UGT1A9	ENST00000354728.5	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	1	NM_021027.3	ENSP00000346768.4
UGT1A7	ENST00000373426.4	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	1	NM_019077.3	ENSP00000362525.3
UGT1A8	ENST00000373450.5	c.1315C>T	p.Arg439Cys	missense_variant	Exon 5 of 5	1	NM_019076.5	ENSP00000362549.4

Frequencies

GnomAD3 genomes AF: 0.0000854 AC: 13 AN: 152204 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000176

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000521 AC: 13 AN: 249424 Hom.: 0 AF XY: 0.0000592 AC XY: 8 AN XY: 135040

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: 0.000116

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000135 AC: 197 AN: 1461880 Hom.: 1 Cov.: 33 AF XY: 0.000122 AC XY: 89 AN XY: 727236

Gnomad4 AFR exome AF: 0.0000597

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000169

Gnomad4 OTH exome AF: 0.0000662

GnomAD4 genome AF: 0.0000854 AC: 13 AN: 152204 Hom.: 0 Cov.: 32 AF XY: 0.0000807 AC XY: 6 AN XY: 74360

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.000176

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000142 Hom.: 0

Bravo AF: 0.0000869

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.0000247 AC: 3

EpiCase AF: 0.000218

EpiControl AF: 0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:5

Uncertain significance, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Dec 23, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 17, 2024	This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 442 of the UGT1A1 protein (p.Arg442Cys). This variant is present in population databases (rs143033456, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with UGT1A1-related conditions. ClinVar contains an entry for this variant (Variation ID: 286999). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt UGT1A1 protein function with a positive predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Apr 20, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Feb 13, 2017	The R442C variant in the UGT1A1 gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The R442C variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The R442C variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. However, this substitution occurs at a position that is not conserved. In silico analysis predicts this variant is probably damaging to the protein structure/function. Therefore, we interpret R442C as a variant of uncertain significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Apr 19, 2016	- -

Crigler-Najjar syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Crigler-Najjar syndrome type 1;C0017551:Gilbert syndrome;C0270210:Lucey-Driscoll syndrome;C1866173:Bilirubin, serum level of, quantitative trait locus 1;C2931132:Crigler-Najjar syndrome, type II Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

UGT1A1-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jul 25, 2024

The UGT1A1 c.1324C>T variant is predicted to result in the amino acid substitution p.Arg442Cys. To our knowledge, this variant has not been reported in the literature in individuals affected with UGT1A1-related conditions. This variant is reported in 0.011% of alleles in individuals of European (Non-Finnish) descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.26
BayesDel_addAF	Benign	-0.091	T
BayesDel_noAF	Benign	-0.15
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.70	D;D;D;D;.;D;D;D;D;D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.14	D
MetaRNN	Uncertain	0.48	T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.37	D
MutationAssessor	Pathogenic	3.8	.;.;H;.;.;.;.;.;.;.
PrimateAI	Benign	0.28	T
PROVEAN	Uncertain	-4.4	D;D;D;D;D;D;D;D;D;D
REVEL	Uncertain	0.34
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;D;D;.;D;D;D;D;D
Vest4		0.32
MVP		0.96
MPC		0.19, 0.35, 0.56, 0.52, 0.74, 0.19, 0.19, 0.64
ClinPred		0.95	D
GERP RS		5.8
Varity_R		0.44
gMVP		0.48

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs143033456; hg19: chr2-234680927;