The absence that makes the difference: choroidal abnormalities in Legius syndrome

Area of Science:

• Ophthalmology
• Genetics
• Medical Diagnostics

Background:

• Neurofibromatosis type 1 (NF1) is a genetic disorder with characteristic café-au-lait macules, freckling, and neurofibromas.
• Choroidal nodules, detected via infrared fundus examination, are highly prevalent in NF1 patients (up to 100%) and proposed as a diagnostic criterion.
• Legius syndrome shares clinical similarities with NF1, leading to potential misdiagnosis.

Purpose of the Study:

• To investigate the presence of choroidal abnormalities in Legius syndrome.
• To determine the specificity of choroidal abnormalities for NF1 diagnosis.
• To assess the potential of choroidal abnormalities as a novel diagnostic criterion for NF1.

Main Methods:

• Examination of the fundus in 16 eyes from eight patients with molecularly confirmed Legius syndrome.
• Utilized confocal scanning laser ophthalmoscopy with infrared monochromatic light for detailed fundus imaging.

Main Results:

• No choroidal abnormalities were observed in any of the examined eyes of Legius syndrome patients.
• This finding contrasts with the high frequency of choroidal abnormalities reported in NF1.

Conclusions:

• The absence of choroidal abnormalities in Legius syndrome supports their diagnostic value for differentiating from NF1.
• Choroidal abnormalities are specific to NF1 and can aid in its accurate diagnosis, distinguishing it from Legius syndrome.