What is a Trio Exome Analysis?
Next generation sequencing of trio family pedigrees offers a powerful approach for the identification of causal mutations for inherited diseases. Trio analysis can be used to identify variants inherited from the parents causing recessive disease or dominant disease. In case of recessive disease, the offspring inherits two defective copies of the gene, one from each parent resulting in the clinical condition. In case of dominant disease, the defective copy of gene is inherited by the offspring from the similarly affected parent. Additionally de novo variants that occur in the offspring but are not present in either of the parents can also be detected.
Trio analysis using either Whole exome or Clinical exome sequencing facilitates analyses of thousands of genes simultaneously to identify genetic alterations like insertions/deletions (indels), single nucleotide variants (SNVs) and copy number variations (CNVs). This comprehensive analysis reduces false positive calls and enables the prioritisation of potential disease causing variants. There is 5-10% increase compared to analyzing proband only.
When do you need to get tested?
When the individuals’ clinical examination, laboratory findings and family history suggests underlying genetic etiology:
- To confirm the genetic diagnosis
- To facilitate medical intervention and treatment
- To guide reproductive planning and assessment of recurrence risk
- To determine the molecular basis of genetically heterogeneous diseases
- To determine the etiology of undiagnosed rare diseases to end the diagnostic odyssey
- To facilitate prognosis
What are the advantages of MedGenome’s Trio Exome Test?
- Mendelian QC to assess the relatedness based on variants obtained
- Combined variant calling increases the accuracy of variant calling and ability to make variant calls in low coverage regions
- Better diagnostic yield compared to analyzing single proband sample
- Simultaneous analysis for all modes of inheritance i.e. autosomal recessive, autosomal dominant, and de novo variants
- Prioritization of variants based on patient phenotype
- Ability to ascertain the significance of clinically relevant variants especially compound heterozygous and de novo variants
Note: Triplet repeat expansions, translocations cannot be detected by this methodology. Genetic changes present outside of the targetted region will not be detected.