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
Consequence
NM_007120.3 stop_gained
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Pathogenic. The variant received 18 ACMG points.
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 | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| UGT1A4 | NM_007120.3 | MANE Select | c.1024C>T | p.Arg342* | stop_gained | Exon 3 of 5 | NP_009051.1 | ||
| UGT1A5 | NM_019078.2 | MANE Select | c.1024C>T | p.Arg342* | stop_gained | Exon 3 of 5 | NP_061951.1 | ||
| UGT1A3 | NM_019093.4 | MANE Select | c.1024C>T | p.Arg342* | stop_gained | Exon 3 of 5 | NP_061966.1 |
Ensembl Transcripts
| Selected | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| UGT1A4 | ENST00000373409.8 | TSL:1 MANE Select | c.1024C>T | p.Arg342* | stop_gained | Exon 3 of 5 | ENSP00000362508.4 | ||
| UGT1A5 | ENST00000373414.4 | TSL:1 MANE Select | c.1024C>T | p.Arg342* | stop_gained | Exon 3 of 5 | ENSP00000362513.3 | ||
| UGT1A3 | ENST00000482026.6 | TSL:1 MANE Select | c.1024C>T | p.Arg342* | stop_gained | Exon 3 of 5 | ENSP00000418532.1 |
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152144Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000281 AC: 7AN: 249052 AF XY: 0.0000371 show subpopulations
GnomAD4 exome AF: 0.0000192 AC: 28AN: 1461894Hom.: 0 Cov.: 36 AF XY: 0.0000248 AC XY: 18AN XY: 727248 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152144Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74318 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:4
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.
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
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.
Gilbert syndrome Pathogenic:2Other:1
UGT1A1-related disorder Pathogenic:1
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
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at