# Neurocutaneous Syndromes > Neurocutaneous syndromes for NEET-PG Paediatrics: NF1 criteria, tuberous sclerosis signs, Sturge-Weber, VHL and chromosome map of phakomatoses. - Canonical URL: https://prepelephant.com/topics/neet-pg/paediatrics/neurocutaneous-syndromes - Exam / course: NEET-PG · Subject: Paediatrics - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Neurocutaneous Syndromes", PrepElephant, https://prepelephant.com/topics/neet-pg/paediatrics/neurocutaneous-syndromes ## Direct answer Six or more café-au-lait macules, an ash-leaf patch under the Wood's lamp in an infant with spasms, or a V1 port-wine stain with contralateral seizures — each opens into a neurocutaneous syndrome (phakomatosis), a congenital disorder of ectodermal structures producing tumours and malformations of brain, skin and eyes. The chromosome map earns marks before anything else: neurofibromatosis type 1 on chromosome 17 (type 2 on 22, "type 2 on 22"), von Hippel-Lindau on chromosome 3, and tuberous sclerosis from TSC1 (hamartin) or TSC2 (tuberin) mutations. Diagnosis is criteria-based — two of seven for NF1 — and surveillance is syndrome-specific: annual blood pressure and ophthalmology for NF1, brain and renal imaging for tuberous sclerosis, intraocular pressure for Sturge-Weber. ## What you must remember - **NF1 diagnostic criteria (two or more of seven):** six or more café-au-lait macules (over 5 mm prepubertal, over 15 mm after), axillary or inguinal freckling, two or more neurofibromas or one plexiform, optic glioma, two or more Lisch nodules, bony lesions (sphenoid dysplasia, tibial pseudarthrosis), or an affected first-degree relative. - **NF1 clinical spine:** autosomal dominant, chromosome 17, neurofibromin (a tumour suppressor); learning difficulty in about half, plexiform neurofibromas, optic pathway glioma screening, hypertension from renal artery stenosis or phaeochromocytoma, and a small but real malignant transformation risk. - **NF2 versus NF1:** bilateral vestibular schwannomas ("bilateral acoustic"), cataracts and few skin signs — chromosome 22, merlin protein; café-au-lait spots and neurofibromas are the NF1 face of the family. - **Tuberous sclerosis complex:** the major features — ash-leaf hypomelanotic macules (Wood's lamp), shagreen patch, facial angiofibromas after age three, ungual fibromas, cortical tubers, subependymal nodules and giant cell astrocytoma, renal angiomyolipoma, cardiac rhabdomyoma (a prenatal clue) and retinal hamartomas; infantile spasms (vigabatrin first line) dominate the neurology. - **Sturge-Weber syndrome:** V1 port-wine stain, ipsilateral leptomeningeal angioma with tram-track calcification, seizures with hemiparesis, and ipsilateral glaucoma — check intraocular pressure in every affected infant; sporadic, GNAQ mutation. - **Von Hippel-Lindau disease:** chromosome 3 — retinal and cerebellar haemangioblastomas, renal cell carcinoma, phaeochromocytoma; lifelong imaging and ophthalmic surveillance in dominant families. - **Ataxia telangiectasia:** bulbar conjunctival telangiectasia after age three, progressive ataxia from toddlerhood, IgA deficiency with sinopulmonary infection, radiosensitivity, elevated alpha-fetoprotein — the clinic-lab combination examiners quote. - **Surveillance rhythm to quote:** NF1 — annual growth, blood pressure, spine (scoliosis) and ophthalmology review with imaging as indicated; tuberous sclerosis — brain magnetic resonance imaging every one to three years for giant cell astrocytoma and renal imaging for angiomyolipoma; Sturge-Weber — ophthalmology in infancy then seizure-focused review. ## How to work through it An infant with developmental stagnation and flexor spasm clusters: Wood's lamp shows three ash-leaf macules; order electroencephalogram (hypsarrhythmia), brain magnetic resonance imaging (subependymal nodules, tubers), echocardiography and renal ultrasound. Diagnosis: tuberous sclerosis complex. Start vigabatrin (first line for tuberous sclerosis-associated spasms), enrol in early intervention, screen the parents, and hand over the surveillance calendar — magnetic resonance imaging for giant cell astrocytoma and renal follow-up, with everolimus or surgery for progressive lesions. A five-year-old sent for "many birthmarks": eight macules over 5 mm, axillary freckling and Lisch nodules on slit lamp make NF1 — chromosome 17 counselling (50 per cent recurrence for an affected parent), annual blood pressure and eye checks, and learning support, since cognition shapes this child's life most. ## How the exam frames it The chromosome pairs (17 NF1, 22 NF2, 3 VHL), the NF1 "two of seven" criteria, and the tuberous sclerosis major-feature list are the three most reliably tested payloads — delivered in that order they secure most marks in a short case. Discriminators follow: Lisch nodules are seen on slit lamp, not with the naked eye (making ophthalmology part of the exam); adenoma sebaceum appears after age three, so a "flushed toddler cheeks" vignette wants the ash-leaf macule answer instead; and a port-wine stain confined to the forehead with glaucoma points to Sturge-Weber, with the contralateral brain responsible for seizures. Indian viva addenda: the tuberous sclerosis-vigabatrin pairing, cost-limited everolimus access, and dominant-family genetic counselling. ## Frequently asked questions ### How many NF1 diagnostic criteria are required for the diagnosis? Two or more of the seven — café-au-lait macules, freckling, neurofibromas, optic glioma, Lisch nodules, bony lesions, or an affected first-degree relative. ### Which skin sign of tuberous sclerosis appears earliest? The ash-leaf hypomelanotic macule, present from birth and highlighted by Wood's lamp examination, often the presenting clue in an infant with infantile spasms. ### Why examine the eyes in every port-wine stain of the forehead? Sturge-Weber syndrome brings ipsilateral glaucoma and leptomeningeal angioma with seizures — intraocular pressure measurement in infancy prevents blindness. ### Which syndrome pairs telangiectasia with immunodeficiency? Ataxia telangiectasia — progressive ataxia, oculocutaneous telangiectasia, IgA deficiency with sinopulmonary infections, elevated alpha-fetoprotein and radiosensitivity. ### What is the drug of choice for spasms in tuberous sclerosis? Vigabatrin, first line for tuberous sclerosis-associated infantile spasms, with periodic ophthalmological monitoring for retinal toxicity during prolonged use.