rs755218546
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PP3PP5
The NM_007120.3(UGT1A4):c.1087G>A(p.Gly363Ser) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000235 in 1,614,052 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G363V) has been classified as Uncertain significance.
Frequency
Consequence
NM_007120.3 missense, splice_region
Scores
Clinical Significance
Conservation
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
UGT1A4 | NM_007120.3 | c.1087G>A | p.Gly363Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000373409.8 | NP_009051.1 | |
UGT1A5 | NM_019078.2 | c.1087G>A | p.Gly363Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000373414.4 | NP_061951.1 | |
UGT1A3 | NM_019093.4 | c.1087G>A | p.Gly363Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000482026.6 | NP_061966.1 | |
UGT1A1 | NM_000463.3 | c.1084G>A | p.Gly362Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000305208.10 | NP_000454.1 | |
UGT1A6 | NM_001072.4 | c.1081G>A | p.Gly361Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000305139.11 | NP_001063.2 | |
UGT1A10 | NM_019075.4 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000344644.10 | NP_061948.1 | |
UGT1A8 | NM_019076.5 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000373450.5 | NP_061949.3 | |
UGT1A7 | NM_019077.3 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000373426.4 | NP_061950.2 | |
UGT1A9 | NM_021027.3 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | ENST00000354728.5 | NP_066307.1 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
UGT1A4 | ENST00000373409.8 | c.1087G>A | p.Gly363Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_007120.3 | ENSP00000362508.4 | ||
UGT1A5 | ENST00000373414.4 | c.1087G>A | p.Gly363Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_019078.2 | ENSP00000362513.3 | ||
UGT1A3 | ENST00000482026.6 | c.1087G>A | p.Gly363Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_019093.4 | ENSP00000418532.1 | ||
UGT1A1 | ENST00000305208.10 | c.1084G>A | p.Gly362Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_000463.3 | ENSP00000304845.5 | ||
UGT1A6 | ENST00000305139.11 | c.1081G>A | p.Gly361Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_001072.4 | ENSP00000303174.6 | ||
UGT1A10 | ENST00000344644.10 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_019075.4 | ENSP00000343838.5 | ||
UGT1A9 | ENST00000354728.5 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_021027.3 | ENSP00000346768.4 | ||
UGT1A7 | ENST00000373426.4 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_019077.3 | ENSP00000362525.3 | ||
UGT1A8 | ENST00000373450.5 | c.1075G>A | p.Gly359Ser | missense_variant, splice_region_variant | Exon 3 of 5 | 1 | NM_019076.5 | ENSP00000362549.4 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152158Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000402 AC: 10AN: 249058 AF XY: 0.0000519 show subpopulations
GnomAD4 exome AF: 0.0000239 AC: 35AN: 1461894Hom.: 0 Cov.: 36 AF XY: 0.0000358 AC XY: 26AN XY: 727248 show subpopulations
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152158Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74328 show subpopulations
ClinVar
Submissions by phenotype
not provided Pathogenic:1Uncertain:1
The c.1084 G>A variant in the UGT1A1 gene has been reported previously in the homozygous state and in the heterozygous state with a second variant in the promotor region in patients with unconjugated hyperbilirubinemia (Aggarwal et al., 2010; Gupta et al., 2015). The c.1084 G>A 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). In vitro studies of this variant using a pCAS2 splicing minigene reporter assay indicate that the c.1084 G>A variant abolishes the natural splice donor site, leading to the creation of a cryptic splice site and a frameshift deletion of 31 nucleotides from the 3-prime end of exon 3, which forms a premature stop codon at position 3 of the new reading frame (Gupta et al., 2015). If c.1084 G>A does not alter splicing, it will result in the G362S missense change. The G362S 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. This substitution occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. We interpret c.1084 G>A as a pathogenic variant. -
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UGT1A1-related disorder Pathogenic:1
The UGT1A1 c.1084G>A variant is predicted to result in the amino acid substitution p.Gly362Ser. This variant has been reported in the homozygous state in an individual with Crigler-Najjar syndrome and in the heterozygous state in individuals with unconjugated hyperbilirubinemia (Gupta et al. 2015. PubMed ID: 26716871; Aggarwal et al. 2009. PubMed ID: 19953640; Mi et al. 2019. PubMed ID: 31467903). This variant is located within the last base of exon 3 and is predicted to alter splicing based on available splicing prediction programs (Alamut Visual Plus v1.6.1). In addition, a functional study showed that this variant impacts splicing (Figure 4, Gupta et al. 2015. PubMed ID: 26716871). This variant is reported in 0.033% of alleles in individuals of South Asian descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-234676582-G-A). 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
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Crigler-Najjar syndrome type 1 Pathogenic:1
The missense/ splice region c.1084G>A p.Gly362Ser variant in the UGT1A1 gene has been reported previously in a homozygous state in individuals affected with Crigler-Najjar syndrome 2 CNS2. In vitro studies of this variant using a pCAS2 splicing minigene reporter assay indicate that the c.1084 G>A variant abolishes the natural splice donor site, leading to the creation of a cryptic splice site and a frameshift deletion of 31 nucleotides from the 3-prime end of exon 3, which forms a premature stop codon at position 3 of the new reading frame Gupta et al., 2015. This variant is reported with an allele frequency of 0.004% in the gnomAD Exomes and novel in 1000 Genomes. This variant has been reported to the ClinVar database with varying interpretations: Pathogenic / Uncertain Significance. The amino acid Glycine at position 362 is changed to a Serine changing protein sequence and it might alter its composition and physico-chemical properties. The amino acid change p.Gly362Ser in UGT1A1 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Pathogenic. -
Crigler-Najjar syndrome, type II Pathogenic:1
The missense / splice region c.1084G>A(p.Gly362Ser) variant in UGT1A1 gene has been reported previously in homozygous state in individual(s) affected with Crigler-Najjar syndrome 2 (CNS2) (Gupta et al., 2015). This variant is reported with the allele frequency of 0.004% in the gnomAD Exomes and novel in 1000 Genomes. This variant has been reported to the ClinVar database with varying interpretation: Pathogenic / Uncertain Significance. The amino acid Gly at position 362 is changed to a Ser changing protein sequence and it might alter its composition and physico-chemical properties. The amino acid change p.Gly362Ser in UGT1A1 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. In vitro studies of this variant using a pCAS2 splicing minigene reporter assay indicate that the c.1084 G>A variant abolishes the natural splice donor site, leading to the creation of a cryptic splice site and a frameshift deletion of 31 nucleotides from the 3-prime end of exon 3, which forms a premature stop codon at position 3 of the new reading frame (Gupta et al., 2015). For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at