"often prone to" is correct and usable in written English.
You can use this phrase to describe the frequency with which someone or something tends to experience a certain situation or emotion. For example, "The elderly are often prone to loneliness."
(It went over big in the V.I.P. section, where people are often prone to similar thoughts).
The shares are tightly held, and often prone to bouts of volatility.
It took a pinball in the area to flummox a home defence too often prone to jitters.
But the monthly estimates of job creation are notoriously volatile, confounding forecasts almost every month and often prone to substantial revision in the months that follow.
While Mr. Ahmadinejad is often prone to exaggeration, outside experts said that clearly Iran was on a path to producing more reliable, longer-range missiles.
Naturally enough, that also means that they are often prone to sum up their experiences as a matter of procedure and technical detail.
Hall played an electric instrument often prone to hyperbole with an irresistibly quiet delicacy, and his improvisations were as shapely as fine songs.
I want to drink in that moment when the sun's rays touch my skin and banish the darkness I am often prone to carrying inside.
By definition, it's about avoiding forms of expression or action that are perceived to exclude, discriminate or insult groups of people who are socially disadvantaged, or often prone to discrimination.
The suit centers on the use of what is essentially solitary confinement -- prisoners call it the "box" -- as a tool to manage the state's 7,300 mentally ill inmates, who are often prone to inappropriate outbursts, fights and disobedience.
Kongo's system of manikongo succession was often prone to disputes, frequently between sons or between sons and brothers of former kings, and at times the rivals would form factions, some of which were long-lived.
