Below are the common clinical features of those diagnosed with Floating–Harbor syndrome. Patients will show varying degrees of some or all FHS symptoms. Facial abnormalities are the most defining aspects of those diagnosed with this disease.

The differential diagnosis of broad thumbs includes Rubinstein-taybi syndrome, where they are a cardinal feature. FHS is also in the differential, which logically agrees with the thought that the disease is a result of a mutation in SRCAP, as this gene interacts with CBP.

The cause of feline hyperesthesia syndrome is unknown. Some experts believe FHS to be a form of epilepsy, while others believe it is a behavioural disorder triggered by trauma. Noting that affected cats tend to be dominating rather than submissive, some research argues that FHS is conflict displacement in which the cat acts out thwarted territorial disputes on its own body.

Although any age, breed, or sex of cat can develop feline hyperesthesia syndrome, those most susceptible include the Siamese, Burmese, and Himalayan breeds.

During an episode cats show a number of typical signs, including skin rolling or twitching, compulsive self-grooming, self-directed pouncing, or aggressive behaviour such as biting or attacking the tail. There may also be pupil dilation, vocalisation and a general increase in activity.