Whole Exome Sequencing (WES)

Description

Which Whole Exome Sequencing (WES) tests are available ?

  • WES analysis of patient only
  • WES analysis of patient and 2 parents to detect de novo variants
  • WES analysis of 2 siblings and 2 parents to detect autosomal recessive variants
  • WES analysis of 3 affected family members to detect autosomal dominant variants

Which patients should be tested by “whole exome” next-generation sequencing (NGS)?

  • Patients who have exhausted currently available genetic testing and do not yet have a molecular diagnosis
  • Patients with a long differential diagnosis or genetically very heterogeneous disorder (eg deafness, retinitis pigmentosa, cardiomyopathy) that makes sequential testing cost-prohibitive

Which analysis is performed?

  • Approximately 37 Mb (214.405 exons) of the Consensus Coding Sequences (CCS) are enriched from fragmented genomic DNA by > 340.000 probes designed against the human genome (Nextera Rapid Capture Exome, Illumina)
  • The generated library is sequenced on an Illumina NextSeq or HiSeq 4000 platform (Illumina)
  • All exons and intron boundaries (+/-20 bp) were analyzed
  • Relevant variants identified by NGS are Sanger sequenced to exclude NGS artefacts
  • All relevant variants are in-house analyzed for their possible pathogenicity and clinical relevance

Which analysis is not performed?

  • Analysis of introns
  • Analysis of the mitochondrial genome
  • Deletion-duplication testing
  • Analysis of repeats (eg FMR1 repeat)

What will be in the report?

  • Pathogenic variants and variants of unknown significance (VUS) in genes that are:
    • Previously implicated in a human disorder similar to the affected individual
    • Could be hypothesized to be related to the cause of the disorder due to their relationship to other genes or particular function

What will not be in the report?

  • Non-paternity, unless specifically requested
  • Carriership of recessive variants, unless specifically requested
  • Late-onset dominant variants not related to the proband’s disorder (eg BRCA1)
  • Benign and likely benign variants

Sample

What is required?

  • 30 µg of DNA or 10 ml EDTA blood of proband and both parents
  • Informed consent if needed locally
  • Clinical information about the patient
  • A pedigree

Why should you send samples of the parents together with that of the proband?

  • Comparing the proband’s exomic data to that of the parents will significantly increase the sensitivity of the test as it will maximize the likelihood of identifying the disease-causing variant(s), and decrease the chance of obtaining variants of unknown significance (VUS)

Turnaround Time

The TAT is less than 2 months.

Price

  • WES analysis of patient only: 1500 Euro
  • WES analysis of patient and 2 parents to detect de novo variants: 2500 Euro
  • WES analysis of 2 siblings and 2 parents to detect autosomal recessive variants: 2700 Euro
  • WES analysis of 3 affected family members to detect autosomal dominant variants: 2700 Euro

Price List

Whole Exome Sequencing (WES)

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