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Allied Condition – Legius Syndrome

People with Legius Syndrome may not affected by nerve tumours, but can still benefit from the services of Nerve Tumours UK such as our Helpline and Specialists. Our connections to the Genetic Centres in the UK, enable us to at the very least, direct your need for support. 

Legius Syndrome, also known as 'NF1 – like Syndrome' shares symptoms with Neurofibromatosis Type 1 (NF1), but does not lead to neurofibromas (nerve tumours).

Legius Syndrome is named after the Belgian doctor Professor Eric Legius who first identified it as a distinct condition. It is also called SPRED1 and has been known as “NF1-like syndrome” because of the similarities the conditions share, and the location of the genetic “misprint” that gives rise to this condition. The main difference between Legius and NF1 is that patients do not develop neurofibromas.

Legius Syndrome has some similarities with NF1 but as molecular genetic testing has developed, it became apparent that this is a separate and different condition. 

NF1 is located on chromosome 17. Legius Syndrome is located on chromosome 15.

Legius Syndrome is a dominant condition which means there is a 50% chance of an affected parent passing it on to each of their children.

What is Legius Syndrome?

Legius Syndrome is a condition that is characterised by changes in skin pigmentation (colouring). Almost everyone with Legius Syndrome has multiple café au lait patches on their skin. These patches look the same as the ones you would see on someone who has NF1.

People with Legius Syndrome also have freckling in the armpit and groins. They also tend to have a larger than average head and mild learning difficulties. These characteristics are also seen in NF1. The main difference between Legius and NF1 is that patients do not develop neurofibromas (nerve tumours). Nor do they have any of the health complications that are linked to NF1.

How can the doctor tell if I have NF1 or Legius Syndrome?

If a patient is referred to the regional genetics service because they have café au lait patches and freckling, NF1 will be the most likely explanation. If the doctor thinks there is some doubt about the diagnosis and the situation needs clarifying, a genetic test can be undertaken.

About 95% of children who have more than 6 café au lait patches will go on to develop NF1.

Most individuals who are diagnosed with Legius Syndrome will have a parent who has the same condition.

It is important to be clear whether a person has NF1 or Legius Syndrome to ensure the correct diagnosis has been made in the first place, so the family has accurate information.

Legius Syndrome is managed in a different way to NF1. Children with Legius Syndrome do not need the same health checks throughout childhood as a child with NF1 because they do not share the risk of NF1-related health complications. However, a developmental assessment should be undertaken to ensure appropriate resources are in place to support the child if necessary.

Masterclasses in NF: Constitutional Mismatch Repair Deficiency Syndrome as Differential Diagnosis to NF1/Legius Syndrome - Prof. Dr. Katharina Wimmer

Constitutional Mismatch Repair Deficiency Syndrome as Differential Diagnosis to NF1/Legius Syndrome

Prof. Dr. Katharina Wimmer, Medical University of Innsbruck

Masterclasses in NF: Rare NF1-Associated Tumors in Adults - Eric Legius & Prof. Ellen Denayer

Masterclasses in NF: Rare NF1-Associated Tumors in Adults

Eric Legius, MD, PhD, University Hospital Leuven

Prof. Ellen Denayer, University Hospital Leuven

Masterclasses in NF: Optimising Hearing Outcomes in NF2-Related Schwannomatosis - Simon Freeman

Masterclasses in NF: Optimising Hearing Outcomes in NF2-Related Schwannomatosis

Simon Freeman, MPhil FRCS, Manchester Royal Infirmary and Salford Royal Hospital

Masterclasses in NF: NF1 Dermatological Manifestations - Pierre Wolkenstein, Laura Fertitta & Sirkku Peltonen

Masterclasses in NF: NF1 Dermatological Manifestations

Pierre Wolkenstein, MD, PhD, Hopital Henri-Mondor, Paris, France

Laura Fertitta, MD, Hôpital Universitaire Henri Mondor

Sirkku Peltonen, MD, PhD, University of Gothenberg, Sweden

Masterclasses in NF: Breast Cancer in NF1 - Gareth Evans

Masterclasses in NF: Breast Cancer in NF1

Gareth Evans, MD, University of Manchester, UK

Masterclasses in NF: Pain in Non-NF2-Related Schwannomatosis - David Pang

Masterclasses in NF: Pain in Non-NF2-Related Schwannomatosis

David Pang, MD, ChB. Guys and St Thomas' Hospital NHS Trust, London

Masterclasses in NF: Distinguishing Non-NF2-Related from NF2-Related Schwannomatosis - Clinical and Genetic Approaches - Said Farschtschi

Masterclasses in NF: Distinguishing Non-NF2-Related from NF2-Related Schwannomatosis - Clinical and Genetic Approaches

Said Farschtschi, MD, University Medical Center, Hamburg-Eppendorf, Germany

Masterclasses in NF: NF1 Pre-Implantation Genetic Diagnosis - Eric Legius & Prof. Ellen Denayer

Masterclasses in NF: NF1 Pre-Implantation Genetic Diagnosis

Eric Legius, MD, PHD, University Hospital of Leuven, Belgium

Prof. Ellen Denayer, University Hospital of Leuven, Belgium

NF2 Working Together: from a tentative diagnosis and beyond

Understanding the impact that a tentative diagnosis has on a parent. Information and access to the existing NTUK and Specialist Nerve Tumours medical and non medical care network.

NF1 Working Together Part 2: from a tentative diagnosis and beyond

Understanding the impact that a tentative diagnosis has on a parent. Information and access to the existing NTUK and Specialist Nerve Tumours medical and non medical care network.

NF1 Working Together Part 1: from a tentative diagnosis and beyond

Understanding  the impact that a tentative diagnosis has on a parent. Information and access to the existing NTUK and Specialist Nerve Tumours medical and non medical care network.

Masterclasses in NF: Surgery in NF2 - Michel Kalamarides & Andrew King

Masterclasses in NF: Surgery in NF2

Michel Kalamarides, MD, PhD, Hôpital Pitié-Salpêtrière, Paris, France

Prof Andrew King, MBBS FRCS FRCS(SN), Salford Royal Hospital, Manchester, United Kingdom. Member of the MAB of Nerve Tumours UK

Masterclasses in NF: Cognition and Behaviour in NF1: Phenotype and Treatment Approaches - Shruti Garg, Andre Rietman

Masterclasses in NF: Cognition and Behaviour in NF1: Phenotype and Treatment Approaches

Dr Shruti Garg, MBBS, MRCPsych, MMedSci, PhD, Royal Manchester Children’s Hospital, United Kingdom. Member of the MAB of Nerve Tumours UK

Andre Rietman, PhD, Erasmus University Medical Center, Rotterdam, Netherlands

Masterclasses in NF: Emotional Challenges in NF1, NF2 and Schwannomatosis - Susie Henley, Thomas Pletschko & Verena Rosenmayr

Masterclasses in NF: Emotional Challenges in NF1, NF2 and Schwannomatosis

Susie Henley, DClinPsy, PhD, Guy’s and St Thomas’ NHS Foundation Trust, London UK

Thomas Pletschko, PhD, Medical University of Vienna, Austria

Verena Rosenmayr, Clinical Psychologist, Medical University of Vienna, Austria

Masterclasses in NF: NF1 Pediatric Management - Rianne Oostenbrink

Masterclasses in NF: NF1 Pediatric Management

Rianne Oostenbrink, MD, PhD, Erasmus University Medical Center, Rotterdam, Netherlands

Masterclasses in NF: Associated Glioma in Children - the Optic Pathway and Beyond - Amedeo Azizi

Masterclasses in NF: Associated Glioma in Children - the Optic Pathway and Beyond

Amedeo Azizi, MD, PhD, Head of the Paediatric Neurofibromatosis Program and Paediatric Neuro-Oncology Program, Medical University of Vienna, Austria

Masterclasses in NF: NF1 Orthopedic Manifestations - Eric Legius and Christophe Glorion

Masterclasses in NF: NF1 Orthopedic Manifestations

Eric Legius, MD, PhD. Head of Clinical Genetics Department of the University Hospital Leuven, Belgium

Christophe Glorion, MD, PhD, Department of Paediatric Orthopedic and Traumatologic Surgery, Hopital Necker-Enfants Malades, Paris, France. 

Masterclasses in NF: NF1 Malignant Peripheral Nerve Sheath Tumours - Rosalie Ferner and Viktor-Felix Mautner

Masterclasses in NF: NF1 Malignant Peripheral Nerve Sheath Tumours

Prof Rosalie Ferner, Consultant Neurologist and Lead Clinician for Neurofibromatosis, Guy's and St. Thomas' NHS Foundation Trust, London. Member of the MAB of Nerve Tumours UK and Trustee of Nerve Tumours UK

Viktor-Felix Mautner, MD, PhD. University Medical Centre in Hamburg-Eppendorf, Germany. Head of NF Outpatient Department

Masterclasses in NF - Neurofibromatosis Type 1: Cutaneous Neurofibromas - Pierre Wolkenstein and Sirkku Peltonen

Masterclasses in NF - Neurofibromatosis Type 1: Cutaneous Neurofibromas

Pierre Wolkenstein, MD, PhD. Hopital Henri-Mondor, Paris, France. Head of the Department of Dermatology

Sirkku Peltonen MD, PhD. University of Gothenberg, Sweden. Professor of Dermatology

INFER (International NF Educational Resources) is a series of online educational lectures for medical professionals by leading neurofibromatosis experts. The Masterclasses take place online approximately once a month, each on a different topic, and include real-time interaction between the expert presenter and the participants. The presentations are conducted in English, with real-time audio interpretation available in 6 additional languages: French, German, Italian, Portuguese, Russian, and Spanish. A recording of each INFER masterclass is then be made available online in each language for those who could not attend an event. INFER is an initiative of Children’s Tumor Foundation Europe, supported by an educational grant from AstraZeneca. https://ctfeurope.org/research/masterclasses-in-nf

BPNA Keynote Lecture - Prof Rosalie Ferner - Neurofibromatosis 1 in the 21st Century

‘Neurofibromatosis 1 in the 21st Century’

Keynote Lecture at the 48th British Paediatric Neurology Association Annual Scientific Meeting on 21st January 2022

Prof Rosalie Ferner, Consultant Neurologist and Lead Clinician for Neurofibromatosis, Guy's and St. Thomas' NHS Foundation Trust, London. Member of the MAB of Nerve Tumours UK and Trustee of Nerve Tumours UK