NM_007120.3:c.1024C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_007120.3(UGT1A4):​c.1024C>T​(p.Arg342*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,614,038 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

UGT1A4
NM_007120.3 stop_gained

Scores

2
2
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11O:1

Conservation

PhyloP100: -0.698

Publications

24 publications found
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 2-233767873-C-T is Pathogenic according to our data. Variant chr2-233767873-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 12269.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_007120.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
UGT1A4
NM_007120.3
MANE Select
c.1024C>Tp.Arg342*
stop_gained
Exon 3 of 5NP_009051.1
UGT1A5
NM_019078.2
MANE Select
c.1024C>Tp.Arg342*
stop_gained
Exon 3 of 5NP_061951.1
UGT1A3
NM_019093.4
MANE Select
c.1024C>Tp.Arg342*
stop_gained
Exon 3 of 5NP_061966.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
UGT1A4
ENST00000373409.8
TSL:1 MANE Select
c.1024C>Tp.Arg342*
stop_gained
Exon 3 of 5ENSP00000362508.4
UGT1A5
ENST00000373414.4
TSL:1 MANE Select
c.1024C>Tp.Arg342*
stop_gained
Exon 3 of 5ENSP00000362513.3
UGT1A3
ENST00000482026.6
TSL:1 MANE Select
c.1024C>Tp.Arg342*
stop_gained
Exon 3 of 5ENSP00000418532.1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152144
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000281
AC:
7
AN:
249052
AF XY:
0.0000371
show subpopulations
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:
0.0000180
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000192
AC:
28
AN:
1461894
Hom.:
0
Cov.:
36
AF XY:
0.0000248
AC XY:
18
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000151
AC:
13
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
3
5
8
10
13
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152144
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74318
show subpopulations
African (AFR)
AF:
0.0000724
AC:
3
AN:
41422
American (AMR)
AF:
0.00
AC:
0
AN:
15268
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000447
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:11Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:4
May 24, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The UGT1A1 c.1021C>T; p.Arg341* variant (rs72551349, ClinVar Variation ID 12269) is reported in the literature in several individuals affected with non-hemolytic unconjugated hyperbilirubinemia (Maruo 2003, Zubaida 2019). While individuals with Crigler-Najjar type I were homozygous for this particular UGT1A1 variant, both Crigler-Najjar type II and Gilbert syndrome individuals were compound heterozygous carriers. This variant is found in the general population with an overall allele frequency of 0.0032% (9/280454 alleles) in the Genome Aggregation Database (v2.1.1). In vitro functional analyses demonstrate no residual enzyme activity when homozygous, and partial activity in heterozygous state (Maruo 2003). Based on available information, this variant is considered to be pathogenic. References: Maruo Y et al. Co-occurrence of three different mutations in the bilirubin UDP-glucuronosyltransferase gene in a Chinese family with Crigler-Najjar syndrome type I and Gilbert's syndrome. Clin Genet. 2003 Nov. PMID: 14616765. Zubaida B et al. Spectrum of UGT1A1 variants in Pakistani children affected with inherited unconjugated hyperbilirubinemias. Clin Biochem. 2019 Jul. PMID: 31145902.

Mar 04, 2025
Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Apr 06, 2018
Genetic Services Laboratory, University of Chicago
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Nov 01, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg341*) in the UGT1A1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in UGT1A1 are known to be pathogenic (PMID: 23290513). This variant is present in population databases (rs72551349, gnomAD 0.02%). This premature translational stop signal has been observed in individual(s) with UGT1A1-related conditions (PMID: 14616765). ClinVar contains an entry for this variant (Variation ID: 12269). For these reasons, this variant has been classified as Pathogenic.

Crigler-Najjar syndrome type 1 Pathogenic:3
Nov 01, 2003
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Mar 22, 2022
3billion
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic/likely pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000012269, PMID:8102509). It is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.0000360). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline.

CENTOGENE GmbH and LLC - Guiding Precision Medicine
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Gilbert syndrome Pathogenic:2Other:1
Nov 01, 2003
OMIM
Significance:Affects
Review Status:no assertion criteria provided
Collection Method:literature only

Dec 26, 2019
Al Jalila Children’s Genomics Center, Al Jalila Childrens Speciality Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

May 04, 2022
Mendelics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

UGT1A1-related disorder Pathogenic:1
May 16, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The UGT1A1 c.1021C>T variant is predicted to result in premature protein termination (p.Arg341*). This variant has been reported as homozygous in individuals with Crigler-Najjar syndrome 1 (Moghrabi et al. 1993. PubMed ID: 8102509; Maruo et al 2003. PubMed ID: 14616765; Zubaida et al. 2019. PubMed ID: 31145902; Cheema et al. 2020. PubMed ID: 33083013). This variant is reported in 0.016% of alleles in individuals of South Asian descent in gnomAD. Nonsense variants in UGT1A1 are expected to be pathogenic. This variant is interpreted as pathogenic.

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 Pathogenic:1
Jun 22, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.44
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
35
DANN
Uncertain
1.0
Eigen
Uncertain
0.21
Eigen_PC
Benign
-0.092
FATHMM_MKL
Benign
0.086
N
PhyloP100
-0.70
Vest4
0.73
GERP RS
4.1
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
Splicevardb
2.0
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

Other links and lift over

dbSNP: rs72551349; hg19: chr2-234676519; API