<prompt> Leisch nodules are seen inSLERheumatoid arthritisNeurofibromatosis type IAnkylosing spondylitis  <response>: C Neurofibromatosis type I NEUROFIBROMATOSIS TYPES TYPE 1 NF-1 Peripheral neurofibromatosis Von Recklinghausens disease Incidence 1 in 3 000 Gene on long arm of chromosome 17 Diagnostic criteria: Devised by National Institute of Health in 1987 Require 2 or more of the following Cafe au lait spots 6 or more 5mm prepubertal 15mm postpubertal Freckling Axillary or inguinal Neurofibromas Two or more neurofibromas of any sort OR One plexiform neurofibroma Optic glioma Leisch nodules Two or more Distinctive osseous lesion Sphenoid dysplasia Thinning of long bone cortex with pseudarthrosis First degree relative with neurofibromatosis Parent, sibling or offspring NEUROFIBROMATOSIS 2 Central neurofibromatosis Incidence 1 in 50 000 Gene on long arm of chromosome 22 Features Two types Multiple CNS involvement Neuraxial neoplasia Meningoneuroplasia Cranial schwannoma Bilateral acoustic neuromas Isolated Dermal lesions unusual 