Algorithm for testing first-degree relatives of an individual with a pathogenic or likely pathogenic variant in the VHL gene

Algorithm for testing first-degree relatives of an individual with a pathogenic or likely pathogenic variant in the VHL gene

Approximately 20% of pathogenic or likely pathogenic variants in VHL arise as de novo mutations. Thus, testing the parents is a reasonable first step for a newly identified affected individual. VHL is an autosomal dominant disease. Children of an affected individual have an approximately 50% chance of carrying the variant and of being affected. All individuals who carry the variant should be offered counseling and surveillance for VHL-associated tumors. Refer to UpToDate for further information about VHL and general information and caveats related to genetic testing.

VHL: von Hippel-Lindau.

* Both parents can be tested simultaneously, if preferable. If both parents are unavailable for testing, if only one parent is available and they test negative, or if there is a question about biological parentage, it is reasonable to evaluate the affected individual's siblings and children for the variant. If parentage is assured and both parents test negative for the variants, the affected individual's siblings generally do not require testing (unless mosaicism is suspected).

¶ There may be rare cases where a parent is a carrier and exhibits mosaicism, which may result in the blood-based test being negative but occult disease manifestations being present. If both parents test negative and there is suspicion that mosaicism exists, siblings may be tested as well.

Graphic 128058 Version 3.0

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Algorithm for testing first-degree relatives of an individual with a pathogenic or likely pathogenic variant in the VHL gene