Are there neurological or psychological disorders that do not affect emotions per se, but affect how they are expressed physically by the body?
For example, normally positive emotions are associated with the tips of the lips curling upwards; do some people express positive emotions in different ways?
Alternatively, when an average person finds something funny, for some period of time they breathe abnormally (so-called laughter); could some people's reaction entail e.g. blinking instead of that?
This is usually referred to as emotional expression or affect display, which can be verbal as well as non-verbal, whereas body language is exclusively non-verbal, and not exclusive to emotion.
This function can certainly go wrong:
There are a few disorders that show deficiency in emotional expression and response. These include alexithymia, autism, hypomimia and involuntary expression disorder.
And also:
Disorders involving ... reduced affect displays most commonly include schizophrenia, post traumatic stress disorder, depression, autism and persons with traumatic brain injuries.
However, afflicted individuals do not typically substitute one expression for another - they usually either do not express some emotions (eg, Spock, who would have been diagnosed with alexithymia), or they express some emotions inappropriately (eg, the Joker, who presumably suffers from PBA). It's unlikely that someone would express happiness by tapping their foot, or laughter by blinking their eyes.
