---
title: Splicing variants
description: Splicing information is used by our Germine Variant Classification implementation to decide whether some rules should be applied or to boost their strength. We use the scSNV as well as MaxEntScan data
---

[Skip to content](https://docs.varsome.com/en/splicing-variants#main-content)

English

Show submenu for translations

[Submit a Support Request](https://docs.varsome.com/en/kb-tickets/new?hsLang=en) [Customer portal](https://docs.varsome.com/support-requests?hsLang=en)

[![varsome-new.png\]](https://docs.varsome.com/hs-fs/hubfs/varsome-new.png?height=40&name=varsome-new.png)](https://docs.varsome.com/en?hsLang=en)

- Editions
  
  Show submenu for Editions

    - [VarSome.com](https://landing.varsome.com/varsome)
    - [VarSome Clinical](https://landing.varsome.com/varsome-clinical)
    - [VarSome Premium](https://landing.varsome.com/varsome-premium)
    - [VarSome API](https://landing.varsome.com/varsome-api)
    - [VarSome Insights](https://landing.varsome.com/varsome-insights)
- About
  
  Show submenu for About

    - [The Company](https://saphetor.com/)
    - [Contact Us](https://landing.varsome.com/contact)
    - [Distributors](https://landing.varsome.com/distributors)
    - [Become a Partner](https://landing.varsome.com/become-varsome-partner)
    - [Community](https://varsome.com/community-contributions/)
    - [Cite VarSome!](https://varsome.com/about/general/varsome-citations/)
- Resources
  
  Show submenu for Resources

    - [Datasources](https://varsome.com/datasources/)
    - [Germline Classification](https://varsome.com/about/resources/germline-implementation/)
    - [Somatic Classification](https://varsome.com/about/resources/somatic-implementation/)
    - [CNV Classification](https://varsome.com/about/resources/sv-implementation/)
    - [Help Center](https://docs.varsome.com/)
    - [Library](https://landing.varsome.com/whitepapers)
    - [IVDR](https://landing.varsome.com/ivdr-whitepaper)
    - [Legal & Compliance](https://docs.varsome.com/en/legal-compliance)
- Blog
  
  Show submenu for Blog

    - [Platform Updates](https://updates.varsome.com/en)
    - [Company News](https://news.varsome.com/en)
    - [VarSome Annotated](https://blog.varsome.com/annotated)

Open main navigation

Close main navigation

- Editions
  
  Show submenu for Editions

    - [VarSome.com](https://landing.varsome.com/varsome)
    - [VarSome Clinical](https://landing.varsome.com/varsome-clinical)
    - [VarSome Premium](https://landing.varsome.com/varsome-premium)
    - [VarSome API](https://landing.varsome.com/varsome-api)
    - [VarSome Insights](https://landing.varsome.com/varsome-insights)
- About
  
  Show submenu for About

    - [The Company](https://saphetor.com/)
    - [Contact Us](https://landing.varsome.com/contact)
    - [Distributors](https://landing.varsome.com/distributors)
    - [Become a Partner](https://landing.varsome.com/become-varsome-partner)
    - [Community](https://varsome.com/community-contributions/)
    - [Cite VarSome!](https://varsome.com/about/general/varsome-citations/)
- Resources
  
  Show submenu for Resources

    - [Datasources](https://varsome.com/datasources/)
    - [Germline Classification](https://varsome.com/about/resources/germline-implementation/)
    - [Somatic Classification](https://varsome.com/about/resources/somatic-implementation/)
    - [CNV Classification](https://varsome.com/about/resources/sv-implementation/)
    - [Help Center](https://docs.varsome.com/)
    - [Library](https://landing.varsome.com/whitepapers)
    - [IVDR](https://landing.varsome.com/ivdr-whitepaper)
    - [Legal & Compliance](https://docs.varsome.com/en/legal-compliance)
- Blog
  
  Show submenu for Blog

    - [Platform Updates](https://updates.varsome.com/en)
    - [Company News](https://news.varsome.com/en)
    - [VarSome Annotated](https://blog.varsome.com/annotated)
- English
  
  Show submenu for translations
- [Submit a Support Request](https://docs.varsome.com/en/kb-tickets/new)
- [Customer portal](https://docs.varsome.com/support-requests)
- [Contact us](https://docs.varsome.com/en/kb-tickets/new)

[Contact us](https://docs.varsome.com/en/kb-tickets/new?hsLang=en)

 How can we help you?

- There are no suggestions because the search field is empty.

1. [VarSome Help Center](https://docs.varsome.com/en?hsLang=en)
2. [FAQ & Troubleshooting](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en)
3. [Pipelines](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#pipelines)

# Splicing variants

#### **Splicing Annotation in VarSome's Germline Variant Classification implementation**

Splicing information is used by our [Germline Variant Classification implementation](https://varsome.com/about/resources/germline-implementation/) to decide whether some rules should be applied or to boost their strength.

We use the scSNV as well as MaxEntScan databases for [splice-site prediction](https://varsome.com/about/resources/germline-implementation/#splicesiteprediction). This is only available for single-nucleotide variants. Variants above the 'ADA Boost Splicing' threshold (0.708) and 'Random Forest Splicing' threshold (0.515) are considered candidate splicing variants. The scSNV splice-site prediction is used in the following rules:

- **BP7**: A synonymous (silent) variant for which splicing prediction algorithms predict no impact to the splice site consensus sequence nor the creation of a new splice site AND the nucleotide is not highly conserved. (Benign, Supporting). The splicing is checked as follows: 
    - The variant is found more than 2 bases away from the next splice site.
    - It is not predicted splicing according to the scSNV database or MaxEntScan predictor.

- **PP3**: Multiple lines of computational evidence support a deleterious effect on the gene or gene product (conservation, evolutionary, splicing impact, etc.) (Pathogenic, Supporting).   
  We exceptionally boost the strength to **'Very Strong' if the variant is predicted splicing and rule PVS1 was not triggered.**

Splicing is also considered in rule:

- **PVS1: **null variant (nonsense, frameshift, canonical ±1 or 2 splice sites, initiation codon, single or multiexon deletion) in a gene where LOF is a known mechanism of disease. (Pathogenic, Very Strong).

In PVS1, **intronic variants within 1 or 2 nucleotides from the exon of the transcript splice site** are considered null variants as defined in this [paper](https://pubmed.ncbi.nlm.nih.gov/30192042/).

#### **Filtering splicing variants in VarSome Clinical**

Splicing variants can be filtered using the [dynamic filters](https://docs.varsome.com/en/dynamic-filters?hsLang=en) feature. The algorithmic filter "[exonic & splicing](https://docs.varsome.com/en/available-algorithmic-filters?hsLang=en)" also includes a criterion to keep splicing candidates. When filtering a splicing variant in VarSome Clinical, we will consider **variants located +/- 10 bp of a known splice site**.

![](https://docs.varsome.com/hubfs/image-png-Apr-25-2022-12-56-40-85-PM.png)

- [Registration & Billing](https://docs.varsome.com/en/registration-billing?hsLang=en#main-content)

    - [User account management](https://docs.varsome.com/en/registration-billing?hsLang=en#user-account-management)
    - [Storage management](https://docs.varsome.com/en/registration-billing?hsLang=en#storage-management)
    - [Pricing and Billing](https://docs.varsome.com/en/registration-billing?hsLang=en#pricing-and-billing)
    - [VarSome Clinical Tokens](https://docs.varsome.com/en/registration-billing?hsLang=en#varsome-clinical-tokens)
- [Management of Samples and Analyses](https://docs.varsome.com/en/management-of-samples-and-analyses?hsLang=en#main-content)

    - [Uploading files](https://docs.varsome.com/en/management-of-samples-and-analyses?hsLang=en#uploading-files)
    - [Managing Samples](https://docs.varsome.com/en/management-of-samples-and-analyses?hsLang=en#managing-samples)
    - [Managing Workflows](https://docs.varsome.com/en/management-of-samples-and-analyses?hsLang=en#managing-workflows)
    - [Launching analyses](https://docs.varsome.com/en/management-of-samples-and-analyses?hsLang=en#launching-analyses)
- [Analysis of the results](https://docs.varsome.com/en/analysis-of-the-results?hsLang=en#main-content)

    - [Analyses](https://docs.varsome.com/en/analysis-of-the-results?hsLang=en#analyses)
    - [Results](https://docs.varsome.com/en/analysis-of-the-results?hsLang=en#results)
    - [Filters](https://docs.varsome.com/en/analysis-of-the-results?hsLang=en#filters)
    - [Reporting](https://docs.varsome.com/en/analysis-of-the-results?hsLang=en#reporting)
    - [Quality Control](https://docs.varsome.com/en/analysis-of-the-results?hsLang=en#quality-control)
- [Legal & compliance](https://docs.varsome.com/en/legal-compliance?hsLang=en)
- [FAQ & Troubleshooting](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#main-content)

    - [Troubleshooting](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#troubleshooting)
    - [General](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#general)
    - [Filters](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#filters)
    - [User Interface](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#user-interface)
    - [Pipelines](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#pipelines)
    - [Features](https://docs.varsome.com/en/faq-troubleshooting?hsLang=en#features)
- [Scientific articles](https://docs.varsome.com/en/scientific-articles?hsLang=en)
- [VarSome API](https://docs.varsome.com/en/varsome-api?hsLang=en)

[![VarSome Logo](https://docs.varsome.com/hs-fs/hubfs/VarSome%20Logo.png?width=200&height=47&name=VarSome%20Logo.png "VarSome Logo")](https://varsome.com)

**Resources**  
[Query Examples](https://varsome.com/about/resources/examples/)  
[Germline Classification](https://varsome.com/about/resources/germline-implementation/)  
[Somatic Classification](https://varsome.com/about/resources/somatic-implementation/)  
[White Papers & Other Resources](https://varsome.com/library/)  
[Cite VarSome](https://varsome.com/about/general/varsome-citations/)  
[System Status](https://status.saphetor.com/)  
[Help Center](https://docs.varsome.com/en?hsLang=en)

<https://www.linkedin.com/showcase/varsome/> <https://twitter.com/varsome?lang=en> <https://www.youtube.com/channel/UCwEorND5-pl_9juijC1YGQA> <https://landing.varsome.com/varsome-clinical?hsLang=en>

**Legal**  
[Terms of Use](https://varsome.com/information/legal/terms/)  
[Privacy Policy](https://varsome.com/information/legal/privacy/)  
[Information Security](https://varsome.com/information/legal/information-security/)

Copyright © 2025, Saphetor SA