Prevalence and Incidence of Xeroderma pigmentosum
Xeroderma pigmentosum: Rare Disease
Xeroderma pigmentosum is listed as a "rare disease" by the Office of
Rare Diseases (ORD) of the National Institutes of Health
(NIH). This means that Xeroderma pigmentosum, or a subtype of Xeroderma pigmentosum,
affects less than 200,000 people in the US population.
Ophanet, who are a consortium of European partners,
currently defines a condition rare when if affects 1 person per 2,000.
They list Xeroderma pigmentosum as a "rare disease".
More information about Xeroderma pigmentosum is available from Orphanet
About prevalence and incidence statistics:
The term 'prevalence' of Xeroderma pigmentosum usually refers to the estimated population
of people who are managing Xeroderma pigmentosum at any given time.
The term 'incidence' of Xeroderma pigmentosum refers to the annual diagnosis rate,
or the number of new cases of Xeroderma pigmentosum diagnosed each year.
Hence, these two statistics types can differ:
a short-lived disease like flu can have high annual incidence but low prevalence,
but a life-long disease like diabetes has a low annual incidence but high prevalence.
For more information see about prevalence and incidence statistics.