Schwannomatosis -SMARCB1/LZTR1; Atypical Familial Rhabdoid Tumour – SMARCB1.

Introduction

Schwannomatosis is a tumour predisposition syndrome showing autosomal dominant inheritance. There is clinical overlap between schwannomatosis and NF2. Diagnostic criteria for schwannomatosis include 2 or more pathologically proved schwannomas and lack of radiographic evidence of vestibular nerve tumor at age more than 18 years (Jacoby et al 1997). Rhabdoid tumors are a highly malignant group of neoplasms that usually occur in children less than 2 years of age.

Referral information

Lymphocyte DNA from individuals satisfying clinical diagnostic criteria for Schwannomatosis (e.g. 2 or more schwannomas no vestibular schwannomas) where NF2 mutation screening has proved negative. All schwannomatosis referrals should be accompanied by a completed clinical questionnaire to assist with the audit of the service (available from www.mangen.org.uk). Lymphocyte DNA from individuals diagnosed with Atypical Familial Rhabdoid Tumour.

Price & reporting times

NHS referrals to this service are paid for where there is an existing specialist commissioning contract for genetic testing. In other cases please contact the lab for prices

Test	Price (£ ex VAT)	TRT *
Mutation scanning	POA	56 calendar days
Single mutation testing	POA	14 calendar days

Test validation & quality assurance - information for users

Germline SMARCB1 mutations are detected in approximately 45% of clinically confirmed schwannomatosis affected familial cases and approximately 90% of cases with atypical familial rhabdoid tumour. LZTR1 mutations are found in approximately 20% of familial schwannomatosis cases. The analytical sensitivity of the NGS screen is 96% following in-house validation.

Sample requirements

4ml EDTA blood sample

Referral guidelines

Please see our referral guidelines for more information.

OMIM Number(s) - 162091

Gene(s) - SMARCB1, LZTR1