[Rare diseases in a medical genetics service of population with social security].

Abstract

Background: Rare diseases (RD) are those that have a low prevalence in the population; ≈80% have a genetic origin, and to diagnose them it takes from 5 to 10 years, and they require evaluations from ≈10 specialists. There is no international consensus on the definition and number of RDs, which affects the availability of resources for their diagnosis, treatment, and research.

Objective: To determine the prevalence of RDs in the Medical Genetics Service of a regional general hospital belonging to the Mexican Institute for Social Security (IMSS), in Puebla, Mexico.

Material and methods: The patients' records who were evaluated by the above-mentioned service from January 2019 to June 2022 were reviewed. Those patients with a diagnosis of a RD were identified, and the prevalence was obtained by using the formula: total number of cases of the disease/number of people in the population at that moment in time.

Results: A total of 798 medical records were reviewed and a prevalence of RDs of 27% was obtained. Those diseases with a prevalence of 1 case per 2000 inhabitants were considered, being 118 different RD. Considering only the 20 rare diseases registered in Mexico in 2022, 11 of these were detected, distributed in 35 patients, with an estimated prevalence of 4.3%.

Conclusion: The prevalence of RDs differs according to the criteria implemented. In Mexico, several diseases that fall within the definition of a RD based on their prevalence were not considered as such until 2022, so the recent recognition of rare diseases included by the World Health Organization will benefit affected patients.