iatroX Rounds #48
The clues
- 1
A 7-year-old boy is brought to the clinic because his parents are concerned about his academic performance and some skin lesions.
- 2
He has eight flat, tan-coloured patches on his trunk and limbs, all of which are larger than five millimetres in diameter.
- 3
The child has a history of developmental delay and his head circumference is currently above the 98th centile.
- 4
On examination, there is prominent freckling in the axillae and several soft, skin-coloured nodules are felt on the torso.
- 5
An ophthalmological review identifies multiple small, raised, brownish hamartomas on the iris of both eyes.
- 6
Brain imaging shows characteristic T2-hyperintense areas in the basal ganglia, and genetic testing confirms a mutation on chromosome 17.
Neurofibromatosis type 1 is an autosomal dominant condition caused by a mutation in the NF1 gene which encodes the tumour suppressor protein neurofibromin. The condition is characterised by various neurocutaneous features and a risk of both benign and malignant tumours.
- At least six café-au-lait spots
- Axillary or inguinal freckling
- Two or more Lisch nodules
- Two or more neurofibromas
for education and entertainment. not medical advice.