Floating-Harbor syndrome is characterised by facial dysmorphism, short stature with delayed bone age, and expressive language delay. Less than 50 cases have been reported in the literature so far. Facial features include a triangular-shaped face, a large bulbous nose with a broad nasal bridge, a wide columella, deep-set eyes with long eyelashes, a wide mouth with thin lips, and a short smooth philtrum. The speech defect is marked by impairment of expressive language and is often associated with a peculiar hypernasal voice. Stature is usually reported to be in the third percentile and between 4 and 6 SD below the mean, but less pronounced short stature has been reported in several cases. Bone age is always delayed. Other variable manifestations include celiac disease, intellectual deficit, dental anomalies (malocclusion, supernumerary upper teeth), a short neck and clinodactyly of the 5th finger. Associated genitourinary and cardiac anomalies have been reported in a few cases. The aetiology is unknown. The majority of reported cases appeared to be sporadic but a few familial cases, with predominantly autosomal dominant inheritance, have been reported. Diagnosis is made on the basis of the clinical phenotype, relying particularly on recognition of the characteristic facial dysmorphism. The differential diagnosis should include other dysmorphic syndromes, in particular Rubinstein-Taybi syndrome and monosomy 22q11 (see these terms). Management is symptomatic only. Patients may benefit from developmental and educational programs and should receive regular orthodontic care. Growth hormone therapy may be of benefit in some patients. The facial dysmorphism is most prominent during mid-childhood but long term follow-up of several patients has shown that the facial dysmorphism becomes less apparent during adulthood. Bone delay may also become less severe with age. Despite the presence of short stature and intellectual deficit, in general patients appear to remain in good health and have a good quality of life.
Last update: June 2007