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About Rare Diseases

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The term rare applies to those diseases affecting a limited number of people with a prevalence below a given cut-off point, which is codified by the legislation of each individual country.
The EU sets this threshold at 0.05% of the population, i.e. when it affects less than 1 in 2,000 inhabitants, while a disease or disorder is defined as rare in the USA when it affects fewer than 200,000 Americans at any given time. There may be as many as 7,000 rare diseases.1,2
Rare diseases are characterized by a broad diversity of disorders and symptoms that vary not only from disease to disease but also from patient to patient suffering from the same disease.2,3

Relatively common symptoms can hide underlying rare diseases leading to misdiagnosis and delaying treatment and they are often chronic, progressive, degenerative, and frequently life-threatening.2

The lack of scientific knowledge and quality information on the disease often results in a delay in diagnosis. Moreover, it is equally difficult for patients to access effective treatment and receive social and medical care for the disease. This often results in a heavy social and financial burdens on patients.3

This is why we focus on treatment and assistance for rare disease sufferers; our commitment concentrates in this field as we believe this therapeutic area to be of great importance and social impact.2,3

We are dedicating our efforts to some main areas: Lysosomal storage disorders (LSDs), Rare Hematology & Rare Ophthalmology.

Patients have been at the centre of what we do for decades.

EACH LIFE IS RARE. AND WE ARE COMMITTED TO THE RAREST ONES.

We believe that no patient should be left behind, which is why we decided to create a business unit specifically dedicated to those with rare diseases. Patients with rare diseases can encounter many difficulties, from getting a timely and accurate diagnosis, to accessing effective medical and social care, resulting in a heavy burden on patients. Chiesi Rare Diseases is specifically committed to these key areas: Lysosomal storage disorders (LSDs), Rare Haematology & Rare Ophthalmology. As such, we believe these therapeutic areas to be of great importance and impact.
  1. Genetic and Rare Diseases Information Center. National Institutes of Health. https://rarediseases.info.nih.gov/diseases/pages/31/faqs-about-rare-diseases. Last accessed: December 19, 2019.
  2. Nguengang Wakap S, et al. Eur J Hum Genet 2019. 
  3. Gainotti S, et al. Int J Environ Res Public Health 2018; 15(10): 2072. 
Lysosomal Storage Disorders
Lysosomal Storage Disorders

Lysosomal storage disorders (LSDs) are a group of about 50 rare inherited metabolic disorders that result from defects in lysosomal function.  New lysosomal storage disorders continue to be identified every day. They are characterized by an abnormal build-up of various toxic materials in the body's cells as a result of enzyme deficiencies. While clinical trials are in progress on possible treatments for some of these disorders, there is currently no approved treatment for many of them, which is why we are dedicating our efforts to three different lysosomal storage disorders: Fabry disease, alpha-mannosidosis, and nephropathic cystinosis.1,2 




  1. National Organization for Rare Disorders (NORD). https://rarediseases.org/rare-diseases/lysosomal-storage-disorders/. Last accessed: December 19, 2019. 
  2. Genetics Home Reference. National Institutes of Health. https://ghr.nlm.nih.gov/condition/alpha-mannosidosis#genes. Last accessed: December 19, 2019.
Rare Hematology
Rare Hematology

Thalassemia and sickle cell disease are two disorders that affect red blood cells.
Both conditions cause problems with hemoglobin, depriving many parts of the body of oxygen.
Both conditions can also lead to serious complications, and, furthermore, both conditions are without a cure.1-4
We believe that patients with thalassemia or sickle cell disease are in serious need of more clinically impactful solutions, which is why our business unit has committed our efforts and resources to do more for these patients.



  1. Genetics Home Reference. National Institutes of Health. https://ghr.nlm.nih.gov/condition/beta-thalassemia. Last accessed: December 19, 2019.
  2. Genetics Home Reference. National Institutes of Health. https://ghr.nlm.nih.gov/condition/sickle-cell-disease. Last accessed: December 19, 2019.
  3. Johns Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/beta-thalassemia. Last accessed: December 19, 2019.
  4. Howard University Hospital. http://www.sicklecell.howard.edu/treatments.htm. Last accessed: December 19, 2019.
Rare Ophthalmology
Rare Ophthalmology

Leber’s Hereditary Optic Neuropathy (LHON) is a rare ophthalmologic condition caused by mutations in mitochondrial DNA.1 Of the mitochondrial DNA disorders, LHON is the most common.2 In most patients with adult-onset of the disease, vision loss is devastating in terms of the impact on their quality of life, and remains permanent.1,2 Currently, there is no cure for LHON, which is why we are dedicating our efforts to develop new products for these patients.2 In addition to helping patients with LHON, we are also exploring other opportunities to help patients with a variety of other rare ophthalmologic conditions.



  1. Genetics Home Reference. National Institutes of Health. https://ghr.nlm.nih.gov/condition/leber-hereditary-optic-neuropathy. Last accessed: December 19, 2019.
  2. Carelli V et al. European Ophthalmic Review. 2019;13(Suppl 2). https://www.touchophthalmology.com/lebers-hereditary-optic-neuropathy-a-global-perspective/.