As well as having the dubious honour of being the first cause of mortality and morbidity in countries with medium and high incomes (1), chronic conditions have become one of the greatest challenges for most healthcare systems, due to their low ability to give a solution to the complexity of processes faced by patients. Alongside the most prevalent chronic conditions, such as diabetes or cancer, there is another group, that of rare diseases, which is highly heterogeneous and has not been paid enough attention to historically. These represent a high impact within healthcare systems, and make them face the paradox of rarity: diseases are rare, but there are many patients who suffer them. Even though these infrequent conditions affect a limited number of persons (2), 6,000 rare diseases are known to exist, which affect 6-8% of the population as a whole.

Most rare diseases are chronic conditions, generating comorbidity and in almost all cases a high level of disability and dependence, thus requiring specialized care and multidisciplinary interventions (3). Those persons suffering them can achieve an acceptable quality of life, though generally their life expectancy is reduced. Having said this, it seems clear that these conditions have a major impact on the lives of patients and their families (4), and require a comprehensive approach in order to improve their quality of life. There are different essential aspects which affect patients, and for which patient associations are demanding special care, including: lack of knowledge about their conditions, difficult access to a correct diagnosis and delay to reach it, lack of high quality care, lack of information and support during treatment, adverse social consequences, difficulty and lack of equity regarding access to treatment, lack of trust in healthcare services, and some lack of interest by healthcare professionals (5). This represents a major challenge for health and social care, which in order to give an answer must provide patients with multidisciplinary and comprehensive care, with centres of referral for specific management of their condition, with connection between different healthcare levels and services, and also taking into account the heterogeneity of diseases and the geographic spread of patients.

The approach of rare diseases, most of which are chronic, cannot be solely focused on the management of clinical variables; social determinants of health must also be considered, such as the lack of equity regarding access to diagnosis or treatment, or the high economic cost arising from the lack of reimbursement for some medications and healthcare products, because these have impact on people’s health. (5). Adopting new forms of care is a priority for the treatment of these patients, and must be based on continuity, coordination or organization of the healthcare processes and settings, which are typically multiple.

The evidence available shows that the development of a nurse with an advanced roles entails a positive impact on the health of patients with different conditions and in different settings (6), with improvement in caregiver overload or the functionality of chronic patients; but there is no evidence available about this advanced nursing roles for addressing persons with rare diseases as a whole. One of the main explanations for this could be the limited knowledge by healthcare professionals, because regardless of their visibility in recent years, the reality of rare diseases still remains unknown for many of them. A recent study reported the lack of knowledge by Nursing students regarding rare diseases; they claimed that they did not feel qualified to treat this type of patients. Knowledge about this matter was higher among graduated nurses (7). These findings showed the lack of pre-graduate training on rare diseases, and a dubious post-graduated training on this matter.

Giving way to new roles in chronicity approach is essential for the success in health intervention. For this aim, nurses must be positioned as cross-sectional healthcare agents, emerging with different models of advanced practice such as case management, thus improving the quality of life of the patients they see and encouraging a better use of health systems. Considering that advanced practice nurses have demonstrated positive results regarding population health, as well as in resource management for patients with complex needs and those with multiple conditions (8), this professional profile of advanced practice would be expected to come up for the care of patients with rare diseases. In this sense, advanced practice nurses could help these patients and their families through coordination between levels of care, as well as with the social and educational settings; they could be key in order to provide accessible care, contributing to an early detection of the condition, genetic counselling, or long-term management of these conditions.

Within the framework of the Master´s Degree in Research and Nursing Care for Vulnerable Populations by the Universidad Autónoma de Madrid, we aimed to examine the advanced competences that nurses use in patients with rare diseases, understanding said competences as complex health interventions, and that any studies analysing them should incorporate this complexity. The research showed that the competences put forward for advanced practice nurses regarding care for patients with rare diseases were not different from those suggested by other authors for complex chronic patients, such as technological or case management (9), but others emerged more specific related to genetics or the development of a humanistic profile..

The need to study the profiles of the nurses working with people with rare diseases is shown by the lack of definition for professional practice competences by nurses in this setting and their impact on health, as well as the informal knowledge that there are nurses with roles similar to advanced practice. The solution to the problems faced by patients with rare diseases is not simple, and given the involvement of nurses in care for this type of patients, it is considered a great opportunity for the profession, considering that they are in the first line of care, accepting new challenges and actively participating in care for patient groups wrongly considered a minority.

Providing training to nurses regarding the needs of patients suffering rare diseases and encouraging them to take on specific roles could favour their empowerment for an active involvement in care for these patients. On the other hand, it is necessary to offer fairer healthcare and social terms to people with rare diseases, through a higher implication of nurses with advanced competences, who will be the main care providers in the community. Knowledge of these skills may help to define the scope of advanced practice in care for these patients, and reinforce the healthcare provided.