Prevalence and Incidence of Prader-Willi syndrome
Prevalance of Prader-Willi syndrome:
estimated 1 per 10,000 - 25,000 people suffer from Prader-Willi syndrome, Genetics Home Reference website ... see also overview of Prader-Willi syndrome.
approx 1 in 10,000 or 0.01% or 27,200 people in USA [Source statistic for calcuation: "estimated 1 per 10,000 - 25,000 people suffer from Prader-Willi syndrome, Genetics Home Reference website" -- see also general information about data sources]
Prader-Willi syndrome: Rare Disease
Prader-Willi syndrome is listed as a "rare disease" by the Office of
Rare Diseases (ORD) of the National Institutes of Health
(NIH). This means that Prader-Willi syndrome, or a subtype of Prader-Willi syndrome,
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 Prader-Willi syndrome as a "rare disease".
More information about Prader-Willi syndrome is available from Orphanet
About prevalence and incidence statistics:
The term 'prevalence' of Prader-Willi syndrome usually refers to the estimated population
of people who are managing Prader-Willi syndrome at any given time.
The term 'incidence' of Prader-Willi syndrome refers to the annual diagnosis rate,
or the number of new cases of Prader-Willi syndrome 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.