Floating-Harbor syndrome

Page most recently updated 7 September 2026

This page focuses on the reported psychiatric associations, which may be the initial presenting manifestation, and on other clinical features that may assist the psychiatrist or primary care physician in identifying the underlying diagnosis, considered through the lenses of the diagnostic lenses framework.

Floating-Harbor syndrome is a rare genetic disorder characterized by short stature, delayed bone age, distinctive facial features, and speech and language impairment. It can occur as an inherited or de novo genetic condition, so absence of a relevant family history does not exclude the diagnosis. Most cases arise de novo, although inherited cases can occur. A distinctive presentation may include the combination of a bulbous nose, short stature, and delayed speech development.

It can present with psychiatric features such as ADHD, anxiety, obsessive-compulsive symptoms, behavioral dysregulation, impulsivity, and difficulties with social interaction. Repetitive behaviors and sensory-processing difficulties may also occur. Cognitive impairment and developmental delay are common, while speech and language impairment is particularly characteristic, often with markedly delayed expressive language and a distinctive speech pattern. These manifestations generally emerge during childhood or development. Although behavioral and temperamental difficulties often lessen with age and may improve substantially by adulthood, some neuropsychiatric difficulties may persist and require ongoing assessment and support.

From a morphologic lens perspective, other features include (but are not limited to):

  • Short neck

  • Proptosis

  • Increased posterior angulation of ears

  • Prominent nasal bridge

  • Bulbous nose

  • Smooth philtrum

  • Short philtrum

  • Wide mouth

  • Brachydactyly

  • Clinodactyly of fifth fingers

  • Broad thumbs and/or broad halluces

Other characteristic features include hypotonia, seizures/epilepsy, and skeletal abnormalities, including brachydactyly, clinodactyly, short thumbs, and clavicular abnormalities. Ophthalmologic features may include strabismus and refractive errors, while hearing impairment may also occur. Additional reported features include early puberty, gastroesophageal reflux, constipation, feeding difficulties, renal abnormalities, genital abnormalities, and congenital heart defects.

Early diagnosis is important to identify and monitor potentially serious developmental, skeletal, cardiac, renal, auditory, and ophthalmologic complications, recognize neuropsychiatric needs early, and institute tailored multidisciplinary surveillance and treatment.

Selected references and further reading — Morphologic lens

Jones KL, Jones MC, del Campo M. Smith's recognizable patterns of human malformation. 8th ed. Philadelphia: Elsevier; 2021.

Reardon W. The bedside dysmorphologist: a guide to identifying and assessing congenital malformations. 2nd ed. Oxford: Oxford University Press; 2016.

Allanson JE, Biesecker LG, Carey JC, Hennekam RCM. Elements of morphology: introduction. Am J Med Genet A. 2009;149A(1):2-5. doi:10.1002/ajmg.a.32601.

Hennekam RCM, Biesecker LG, Allanson JE, Hall JG, Opitz JM, Temple IK, Carey JC; Elements of Morphology Consortium. Elements of morphology: general terms for congenital anomalies. Am J Med Genet A. 2013;161A(11):2726-2733. doi:10.1002/ajmg.a.36249.