Begonya Nafria Escalera
Begonya Nafria
Share4Rare Coordinator

Same symptoms: Same treatment? Same response?

Médico con carpeta informe tratamiento
Many low-prevalence diseases share symptomatology, which makes their diagnosis difficult. Furthermore, even if a treatment is available, each person may respond very differently.

Due to the existence of a large number of rare diseases (ranging from 6,000 to 8,000 according to various sources), it is common for many of them to exhibit similar symptomatology. This circumstance significantly complicates their diagnosis. Furthermore, even in cases where therapeutic options are available for a specific disease, it is vital to recognise that the response to treatment may vary among patients.

The heterogeneity in each individual's metabolism, coupled with the influence of environmental factors on their physiology, plays a crucial role in determining the response level to the same treatment. This reality evidences that medicine is not an exact science, emphasising the significance of adopting a personalised medicine approach whenever feasible. By tailoring treatments to the specific characteristics of each patient, personalised medicine holds the potential to enhance precision in medical practice and achieve better outcomes.

In general, we can create a simple list of possible response outcomes among different patients receiving the same treatment:

  • Satisfactory response: The treatment is effective and produces the desired results.
  • Partial response: The treatment has some effect, but its efficacy is lower than desired.
  • No response: The treatment does not produce any noticeable positive or negative effects.
  • Severe side effects: The treatment leads to significant adverse reactions or complications.
  • Development of drug resistance: Over time, the medication becomes less effective, even if it initially produced a satisfactory response.

It is important to note that this list provides a general overview, and individual responses to treatment can vary significantly. 

In the treatment of a patient, where both the diagnosis and symptoms are critical, physicians aim to consider various clinical and lifestyle factors in an individualised manner. However, in the case of rare diseases that affect a reduced number of patients ("ultra-rare" diseases), the available options are often limited. In such cases, the approach typically involves administering a treatment, closely monitoring the patient's response, and making necessary adjustments to the dosage, schedule, or medication. The focus is on adapting the treatment plan based on the patient's unique needs and closely observing their progress.

Currently, we are aware that identical symptoms can be attributed to different diseases. As a result, specific symptoms can arise from distinct physiological processes, which not only influence the progression of the disease but also guide the selection of the most appropriate treatment. This reality represents a noteworthy shift in the approach to disease diagnosis and treatment, emphasising the significant relevance of genetic findings.

Once again, it is of utmost importance for research on rare diseases to concentrate on studying the natural history of the condition. This involves gaining an understanding of the underlying cause of a specific pathology and how it progresses over time in the absence of any therapeutic interventions. This information serves as a valuable "control group" or comparative data to evaluate the effects of a new treatment during the study phase.

To accomplish this goal, the collaboration of patients and families is vital. Collecting pertinent patient samples, often on an international scale, is the approach that enables clinicians to describe the natural history of the disease and foster concurrent research initiatives. This is where Share4Rare comes into play as a platform, which can serve as a valuable tool for researchers and patients to initiate studies on rare diseases.