Genomic & inherited disorders
What are inherited and genomic imprinting disorders?
Inherited disorders are conditions transmitted from one generation to the next. They arise due to genetic changes which are either small (substitutions, small deletions, inversions, duplications, repeat expansions, etc.) or large (e.g. exonic duplications and deletions, common in the BRCA and dystrophin genes).
Imprinting disorders are not inherited but arise during gamete production or early embryonic development, leading to certain genes being silenced. These can result in developmental disorders such as Prader-Willi syndrome (PWS), Angelman syndrome (AM), Beckwith-Wiedemann syndrome (BWS), or Silver-Russell syndrome (SRS).
Why EQAs are important for genetic tests assessing inherited and imprinting disorders
In inherited genetics and imprinting genomics, the interpretation of the result is equally as important as the test result itself. This is why all our schemes are offered with assessment of interpretation/reporting.
Since patients are usually only tested once, it is crucial that they receive an accurate and reliable genetic result. An incorrectly diagnosed patient with a cancer predisposition, could miss the opportunity to take preventive measures such as prophylactic surgery, resulting in the development of cancer which could have been prevented. It is equally important to correctly identify suitable candidates for cutting edge treatments, such as gene therapies, so ensure the best outcome for as many patients as possible.
Participating in an external quality assessment (EQA) programme provides the reassurance that laboratory performance has been objectively tested by an external agency. If issues do arise during testing or reporting, EMQN will support the laboratory in investigating and improving their processes, through the help of experts in the field.
News
Featured inherited and imprinting disorders EQA schemes
- The hereditary breast and ovarian cancer (HBOC) EQA scheme
The HBOC test is one of the more commonly performed genetic tests. The EQA scheme is offered for HBOC gene panel testing or HBOC targeted BRCA1/BRCA2 testing.
Both assess the genotyping accuracy, clinical interpretation and patient identifiers/clerical accuracy. The scheme has a strong focus on ensuring variant identification and curation within internationally accepted guidelines, and concise and accurate clinical reporting without the risk of misinterpretation.
- The Prader-Willi syndrome (PWS) and Angelman syndrome (AS) EQA scheme
The PWS/AS scheme is the oldest genomic imprinting scheme offered by EMQN (since 2011). Laboratories are expected to perform methylation analysis of PWS/AS critical regions and uniparental disomy/deletion analysis.
The scheme evaluates the genotyping accuracy, clinical interpretation and patient identifiers/clerical accuracy. It emphasises on a clear understanding of the underlying defect in each case and relating this to the clinical referral and recurrence risks. Laboratories also need to be aware of the expected clinical yield when testing for Angelman syndrome and how this may impact a negative test result.
- New: Inherited retinal disorders EQA
EMQN now
offers a comprehensive pilot EQA scheme evaluating the entire genomic
diagnostic pipeline for IRD testing from sample receipt and processing to
analysis and reporting. Ensuring an accurate diagnosis will ensure cutting-edge
gene therapies are available for as many patients as possible.
Important EQA scheme dates
Germline EQA schemes registration deadline: November 30th, 2024, 23:59 GMT
Relevant documents
Many of the best practice guidelines on our resources page relate to genomic and inherited disorders.
External links
No external links available