Prevalence and Incidence of Megalencephaly
Megalencephaly: Rare Disease
Megalencephaly is listed as a "rare disease" by the Office of
Rare Diseases (ORD) of the National Institutes of Health
(NIH). This means that Megalencephaly, or a subtype of Megalencephaly,
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 Megalencephaly as a "rare disease".
More information about Megalencephaly is available from Orphanet
About prevalence and incidence statistics:
The term 'prevalence' of Megalencephaly usually refers to the estimated population
of people who are managing Megalencephaly at any given time.
The term 'incidence' of Megalencephaly refers to the annual diagnosis rate,
or the number of new cases of Megalencephaly 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.