Mutation screening of neurofibromatosis type 1 (NF1) exons 28 and 29 with single strand conformation polymorphism (SSCP): five novel mutations, one recurrent transition and two polymorphisms in a panel of 118 unrelated NF1 patients. Mutations in brief no. 229. Online.

Neurofibromatosis type 1 is a clinically variable disorder caused mostly by small mutations within the NF1 gene on chromosome 17q11.2. We used Single Strand Conformation Polymorphism (SSCP) and radioactive sequencing to screen NF1 exons 28 and 29 from 118 unrelated patients, diagnosed with NF1 according to the NIH criteria, identifying five novel and one recurrent germline mutations, two novel polymorphisms and a variant base exchange. All but one cause protein truncation and represent typical NF1 mutations. There are reports that NF1 patients with mutations in exons 28 and 29 could be at greater risk of developing myeloid leukemia. This question was given consideration in this investigation, but none of the children involved have yet shown any symptoms of myeloid leukemia. 4 out of the 6 mutations were de novo.