Neurocutaneous Syndromes (original) (raw)

2020, Atlas of Dermatoses in Pigmented Skin

NF 1 is the most common single-gene genetic disorder to affect the human nervous system and the estimated prevalence of 2 to 3 cases per 10,000 population (North 2000). It is inherited as a complex autosomal dominant manner due to mutations in germline NF1 tumour suppressor gene (Gutmann et al. 2017). The clinical manifestation varies and almost all develops pigmentary lesions, such as café-aulait macules, skinfold freckling and Lish nodules. Other systemic involvements are skeletal abnormalities (scoliosis, tibial pseudarthrosis and orbital dysplasia), brain tumours (optic pathway gliomas and glioblastoma), peripheral nerve tumours (spinal neurofibromas, plexiform neurofibromas and malignant peripheral nerve sheath tumours), learning disabilities, attention deficits and social and behavioural problems. These will negatively impact quality of life (Ferner et al. 2007). The clinical manifestations according to three major studies are as follows (North 2000). Dermatological Manifestations of NF1 (Friedman 1993) (Table 4.1) 4.1.1 Café-au-lait Spots This is the first clinical manifestation. These macules are varied in sizes, but the typical spot is between 10 and 30 mm in size, ovoid in shape and uniform in colour, although the variations are not uncommon to this. They normally do not appear in the scalp, eyebrow, palms and soles. Its melanocytes are histologically characterised with the presence of giant melanosomes; however, this finding is not unique to NF1 (Figs. 4.1, 4.2 and 4.3).