Partialism refers to a sexual interest with an exclusive focus of a specific part of the body. Partialism is categorized as a paraphilia

Paraphilia

Paraphilia is a biomedical term used to describe sexual arousal to objects, situations, or individuals that are not part of normative stimulation and that may cause distress or serious problems for the paraphiliac or persons associated with him or her...

 in the DSM-IV-TR of the American Psychiatric Association. Individuals with partialism sometimes describe the anatomy of interest to them as having equal or greater erotic attraction for them as do the genitals.

Partialism, such as for the foot

Foot fetishism

Foot fetishism, foot partialism, foot worship, or podophilia is a pronounced sexual interest in feet. It is the most common form of sexual preference for otherwise non-sexual objects or body parts.-Characteristics:...

, occurs both in heterosexual and homosexual individuals.