Prevalence and Incidence of Pterygium syndrome, antecubital
Ophanet, who are a consortium of European partners,
currently defines a condition rare when if affects 1 person per 2,000.
They list Pterygium syndrome, antecubital as a "rare disease".
More information about Pterygium syndrome, antecubital is available from Orphanet
About prevalence and incidence statistics:
The term 'prevalence' of Pterygium syndrome, antecubital usually refers to the estimated population
of people who are managing Pterygium syndrome, antecubital at any given time.
The term 'incidence' of Pterygium syndrome, antecubital refers to the annual diagnosis rate,
or the number of new cases of Pterygium syndrome, antecubital 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.