The results of the following investigations may significantly influence the likelihood of detecting a heritable pathogenic variant in the NF2 gene and are part of clinical care for individuals at risk of NF2:
- head and spine MRI
- hearing evaluation, including brain stem auditory evoked responses (BAER)
- ophthalmologic evaluation if testing criteria not already met
- cutaneous examination
- consider prior or concurrent LZTR1 and SMARCB1 testing in patients with multiple non-vestibular schwannomas.
Due to a high level of somatic mosaicism, NF2 pathogenic variant search and loss of heterozygosity (LOH) testing in tumour tissue is recommended. Consider somatic NF2 (with or without concurrent LZTR1 and SMARCB1) testing (ideally in two separate tumour samples) if tumour tissue is available. Based on the tumour testing results, germline testing may be useful in the proband and/or their relatives. If germline testing is undertaken first and is uninformative, tumour testing should be considered.