Neurofibromatosis type I
 

neurofibroma axillary freckles and café-au-lait spot Café-au-lait spots

There are multiple café-au-lait spots and neurofiborma. There are also multiple freckles at the axilla. The eyelid may  show ptosis or has abnormal shape due to the presence of plexiform neuroma. Other features: proptosis in patient with absent lesser sphenoid wing or optic glioma or meningioma Lisch's nodules in the iris astrocytic hamartoma on the retina

Question:

1. What is the inheritance of neurofibromatosis?

Answer
Neurofibromatosis may be type I or type II. Both are autosomal dominant. Type I is carried on chromosome 17q11.2 whereas type II on chromosome 22.

2. What criteria are needed for the diagnosis of neurofibromatosis type I?

Answer
The diagnosis is clinical and require the presence of two or more of the following:
6 or more café-au-lait spots (the diameter being 5 mm in children and more than 15 mm in adults)
two or more neurofibromas or one plexiform neurofibroma.
freckles in t he axilla or the inguinal region
optic glioma
two or more Lisch's nodules
a distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex with or without pseudoarthroses
a parent, sibling or child with neurofibromatosis according to the above criteria.
 

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