Legius syndrome

Legius syndrome

Legius syndrome (LS) is an autosomal dominant condition characterized by cafe au lait spots. It was first described in 2007 and is often mistaken for Neurofibromatosis type I (NF-1). It is caused by mutations in the SPRED1 gene. It is also known as Neurofibromatosis Type 1-like syndrome (NFLS). The syndrome is named after Eric Legius, Professor at the KU Leuven. It is a RASopathy.

Symptoms

See also: List of conditions associated with café au lait macules

Nearly all patients show multiple Café au lait spots. Other symptoms may include:

• Freckles in the armpits and/or groin
• Lipomas
• Macrocephaly
• Learning disabilities
• ADHD
• Developmental delay

Features common in neurofibromatosis - Lisch nodules, bone abnormalities, neurofibromas, optic pathway gliomas and malignant peripheral nerve sheath tumors - are absent in this condition.

Diagnosis

Genetic testing is necessary to identify the syndrome. The test checks for loss of function mutations in the SPRED1 gene.

Confusion with Neurofibromatosis Type I

The symptoms of Legius syndrome and NF-1 are very similar. This is the reason why the two are easily confused. A genetic test is often the only way to make sure a person has LS and not NF-1. The similarity of symptoms stem from the fact that the different genes affected in the two syndromes code for proteins that carry out a similar task in the same reaction pathway.

An important difference is the absence of tumor growths (Lisch nodules and Neurofibromas which are common in NF-1) in LS.

Because of this difference, Legius syndrome is often seen as the less severe of the two syndromes.

Disease Database

SPRED1 gene variant database

See also

• List of cutaneous conditions
• List of genes mutated in cutaneous conditions