About SF3B1
No gene-level summary was recorded for this case.
No variant summary was recorded for this case.
Five-step scale from benign to pathogenic. This variant is uncertain. Select a step to read what it means.
Uncertain.The recorded classification is uncertain significance.
Gene-level background from the recorded interpretation.
Words with a dotted underline have a short definition. Hover or tap them.No gene-level summary was recorded for this case.
The recorded framework is Not recorded. The criteria and strengths shown below come from the saved assessment; this page does not recalculate the classification.
The applied criteria and their strengths are shown as assessed under the stated framework.
The variant p.Arg625Leu was detected in uveal melanoma and MDS tumors and is associated with aberrant alternative splicing. The SF3B1 R625 codon is a recurrent hotspot where mutations induce neomorphic cryptic 3' splice site selection. The variant was explicitly identified in patient tumors exhibiting the alternative splicing signature (PMID:23861464, PMID:24434863). Mechanistic studies (PMID:26565915) experimentally demonstrated that hotspot mutations in the HEAT domain (residues 622-781) cause aberrant splicing through altered branch point usage, and the authors concluded that functional consequences are similar across hotspot mutations. However, R625L was not directly tested in a controlled experimental system (minigene assay, overexpression, or knockdown rescue), limiting the strength to supporting.
The variant alters Arg625, located within the HEAT domain (H4-H8 repeats, residues 622-781) of SF3B1. This is a well-characterized critical functional domain required for branch point sequence recognition and pre-mRNA splicing. Residue R625 is a statistically significant hotspot in cancer (CancerHotspots.org) and is the most frequently mutated codon in uveal melanoma (PMID:23861464). Mutations in this domain have been experimentally shown to induce neomorphic aberrant splicing activity (PMID:26565915).
The variant is absent from gnomAD v2.1 (exomes) and v4.1 (0/1,614,004 alleles, AF=0.0%), meeting the PM2 threshold of <0.1% allele frequency in population databases for a gene without a CSPEC framework.
REVEL score of 0.865 predicts a deleterious effect on protein function. BayesDel score of 0.3522 is inconclusive. SpliceAI predicts no significant splice impact (max delta score 0.17). While only one of three in silico tools strongly supports pathogenicity, the high REVEL score in a well-conserved functional domain supports a deleterious effect.
No benign criterion marked as applied in the recorded assessment.
gene-specific framework lacked a usable explicit final combination framework, so generic ACMG/AMP 2015 final-combination rules were applied as fallback; applied criteria: PS3 supporting, PM1 moderate, PM2 supporting, PP3 supporting; combination = 1 moderate + 3 supporting, which maps to VUS.
Evidence summaries and captured source records, where available. Missing entries should not be interpreted as negative findings.
gnomAD v4.1: 0 / 1,614,004 alleles. Recorded AF 0. Recorded homozygote count 0.
Absent from gnomAD v2.1.
Not available in gnomAD-Canada v1.0.
Recorded SpliceAI maximum delta score: 0.170. Refer to the recorded PP3/BP4 rationale for interpretation.
A ClinVar laboratory submission summary was not recorded.
OncoKB identified variant-specific curated literature and context relevant to functional review; curated oncogenicity label: Likely Oncogenic.
This variant has previously been reported in somatic cancers (COSMIC; COSV59206122, n = 40 times).
This variant lies in a statistically significant hotspot.
ACMG/AMP criteria under Not recorded, with the data and sources behind each one.
26 criteria with recorded statuses: 4 met · 20 not met · 0 not assessed · 2 not applicable. Open any row for the full reasoning, the rule and the evidence behind it.
One moderate pathogenic criterion (PM1) and three supporting pathogenic criteria (PM2, PS3, PP3) are met.
Under generic ACMG/AMP 2015 combination rules (PMID:25741868), the combination of 1 moderate and 3 supporting pathogenic criteria is insufficient to reach Likely Pathogenic (requires ≥1 Moderate + ≥4 Supporting, ≥2 Moderate + ≥2 Supporting, or other qualifying combinations).
No benign criteria are met.
Final classification: Variant of Uncertain Significance (VUS).
No criteria match.
Every interpreted variant in SF3B1, mapped onto the exon structure of NM_012433.3. Select a row to find it on the plot.
| Protein | Location | Classification | Link |
|---|
This variant is present in gnomAD v4.1 (AF= 0; MAF= 0.00000%, 0/1614004 alleles, homozygotes = 0) and has highest observed frequency in the African/African American population (AF= 0; MAF= 0.00000%, 0/75014 alleles, homozygotes = 0).
Absent from gnomAD v2.1.
Not available in gnomAD-Canada v1.0.
SpliceAI predicts no significant splice impact for this variant (max delta score = 0.17). REVEL score = 0.865. BayesDel score = 0.3522.
4 paper records listed. 3 cited in the classification.
We screened SF3B1 in 105 additional consecutive archival primary uveal melanomas and detected 15 additional mutations (8 p.R625H, 4 p.R625C, 1 p.R625P, 1 p.R625L, 1 p.K666T; Supplementary Table 7).
Location Results section: 'We screened SF3B1 in 105 additional consecutive archival primary uveal melanomas and detected 15 additional mutations (8 p.R625H, 4 p.R625C, 1 p.R625P, 1 p.R625L, 1 p.K666T; Supplementary Table 7).'
Context Patient tumor samples (primary uveal melanoma); Affymetrix HTA2.0 microarrays, RNA-seq, and qRT-PCR for splicing analysis
24 MDS SF3B1 mutated samples cases [K700E (14), H622Q (4), D781G (2), R625L/H/D/C (4)] and 19 SF3B1 mutated UM samples [K625H/C/L/P (16), K666M/T (2), D700E (1)].
Location Results section: '24 MDS SF3B1 mutated samples cases [K700E (14), H622Q (4), D781G (2), R625L/H/D/C (4)] and 19 SF3B1 mutated UM samples [K625H/C/L/P (16)]...'
Context Patient tumor samples; RT-QPCR splicing analysis of UQCC, CRNDE, ANKHD1, GUSBP1, ABCC5 across 161 tumors
all hotspot mutations are co-localized in a limited, positively charged region even though they are distributed across five different HEAT domains... our data suggest the functional consequences on splicing for these changes are similar.
Location Introduction: 'The recurrent hotspot mutations in SF3B1 are found exclusively in the C-terminal HEAT domains (residues 622-781).' Discussion: 'all hotspot mutations are co-localized in a limited, positively charged region...our data suggest the functional consequences on splicing for these changes are similar.'
Context Nalm-6 isogenic cell lines, K562 cells, 293FT cells; RNA-seq, Nanostring, minigene splicing assays, lariat PCR, SILAC proteomics
Screenshots represent source records captured during evidence collection. Select one to view the recorded source content.
The evidence statements recorded by the interpretation pipeline. They have not been reinterpreted by the page.
This variant is present in gnomAD v4.1 (AF= 0; MAF= 0.00000%, 0/1614004 alleles, homozygotes = 0) and has highest observed frequency in the African/African American population (AF= 0; MAF= 0.00000%, 0/75014 alleles, homozygotes = 0).
Absent from gnomAD v2.1.
Not available in gnomAD-Canada v1.0.
This variant is absent from ClinVar.
SpliceAI predicts no significant splice impact for this variant (max delta score = 0.17). REVEL score = 0.865. BayesDel score = 0.3522.
OncoKB identified variant-specific curated literature and context relevant to functional review; curated oncogenicity label: Likely Oncogenic.
This variant lies in a statistically significant hotspot. This variant has previously been reported in somatic cancers (COSMIC; COSV59206122, n = 40 times).
This variant lies in a statistically significant hotspot.