Patricia Maroño

Patricia Maroño

Marketing Assistant

World Neurofibromatosis Day

Today, May 17, is World Neurofibromatosis Day, a genetic disorder in which tumors form in nerve tissue, called neurofibromas, resulting in cutaneous and neurological signs, mainly affecting the quality of life of patients.

Different types of Neurofibromatosis

Three types of neurofibromatosis are differentiated according to the causal gene involved:

97% of patients have neurofibromatosis type 1 caused by alterations in the NF1 gene, which encodes a protein called neurofibromin 1, responsible for cell proliferation. Its main sign is the presence of café-au-lait spots at birth or spots that increase in size and number with age, this being the main diagnostic criterion of the disease. Patients also present axillary or inguinal freckles, cutaneous, subcutaneous or plexiform neurofibromas (tumors affecting the spinal nerve roots).

Neurofibromatosis type 2 is caused by changes in the NF2 gene encoding a protein called merlin, which is involved in cell movement and proliferation. It usually begins in adolescence and its main sign is the appearance of schwannomas (nerve sheath tumors) affecting both vestibular nerves causing hearing loss and deafness.

Finally, the Schwannomatosis is diagnosed in the second or third decade of life and the most common presenting feature is localized or diffuse pain or asymptomatic mass. Schwannomas most commonly affect peripheral nerves and spinal nerves and genetic alterations are found in the SMARCB1 or LZTR1 genes.

The three types of neurofibromatosis follow an autosomal dominant pattern of inheritance, i.e. a single copy of the mutated gene is sufficient to develop the disease.

Diagnosis. Role of genetic studies

The diagnosis of neurofibromatosis is based on clinical and molecular criteria. The manifestations of the disease can be very variable among patients, even within the same family, and many of them can also be characteristic of other diseases, so a genetic study is essential for a correct diagnosis.

Genetic diagnostic tests analyze the patient's DNA in search of mutations in the genes that can cause the disease. The identification of the mutation, in addition to confirming clinical suspicion, allows correct family genetic counseling and the identification of other affected relatives, since 50% of patients have inherited the mutation from their parents.

Neurofibromatosis remains an incurable disease whose treatment is based on a multidisciplinary approach to control the different clinical manifestations. Therefore, having a correct early clinical and molecular diagnosis is key to be able to follow up and monitor these patients adequately, with the aim of anticipating or reducing the symptoms that may develop and improving their quality of life.

  4. Sanchez LD, Bui A, Klesse LJ. Targeted Therapies for the Neurofibromatoses. Cancers (Basel). 2021;13(23):6032. 

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