Although individually rare (fewer than 1 in 2000 people), rare genetic diseases are collectively frequent, affecting a significant number of people worldwide, and stem from copying errors in the genetic code (DNA).

noli's read

The advice relies on a standardized definition of rarity in public health, validated by organizations such as Orphanet and Inserm (institutional source, scientific consensus). Explaining DNA as a code subject to transcription errors is an accurate pedagogical analogy to illustrate genetic mutations. It is correct that, although each pathology is rare, the accumulation of these 6000 to 8000 diseases represents a major public health issue. The assertion that 'this will happen to one of our descendants' is a statistical extrapolation based on the prevalence of human genetic variations, but it should not be interpreted as an individual certainty for every family. The summary faithfully reflects the state of knowledge on medical genetics and the epidemiology of rare diseases.

the sources

No named source held this one up — that absence is part of the verdict.