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