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The phenotype of Floating-Harbor syndrome in 10 patients
Susan M White1, Angela Morgan, Annette Da Costa
1Genetic Health Services Victoria, Royal Children's Hospital, Parkville, Victoria, Australia. sue.white@ghsv.org.au
Insights
Floating-Harbor syndrome (FHS) is a rare genetic disorder characterized by distinctive facial features, short stature, and speech difficulties. This study refines the FHS phenotype, noting behavioral issues and intellectual functioning variations, with no large genomic changes identified.
Area of Science:
- Genetics
- Pediatrics
- Clinical Medicine
Background:
- Floating-Harbor syndrome (FHS) presents diagnostic challenges due to subtle infantile features and overlapping symptoms with common conditions.
- Key FHS characteristics include short stature, speech impairment, and delayed bone age, often requiring expert clinical assessment.
Purpose of the Study:
- To refine the clinical phenotype of Floating-Harbor syndrome across a range of ages.
- To characterize dysmorphic features, behavioral patterns, and intellectual functioning in affected individuals.
- To investigate potential large-scale genomic causes of FHS using microarray analysis.
Main Methods:
- Clinical evaluation of 10 individuals with FHS (ages 7-34) and a mother-daughter pair.
- Detailed assessment of physical characteristics, including facial features and body habitus.
- Bone age measurements, behavioral assessments, speech and language evaluations, and intellectual functioning assessments.
- Microarray analysis in eight patients to detect copy-number variations.
Main Results:
- Delayed bone age was observed, particularly in younger children, with some normal ranges in older individuals.
- Characteristic facial profiles and body habitus were key diagnostic aids.
- Most individuals exhibited significant behavioral problems, including hyperactivity and aggression.
- Severe speech and language disorders were prevalent.
- Intellectual functioning varied from borderline normal to moderate intellectual disability.
- Early puberty and adult heights between 140-155 cm were noted.
- Microarray analysis did not reveal large-scale copy-number genomic changes.
Conclusions:
- FHS is a complex syndrome with a spectrum of clinical manifestations beyond initial descriptions.
- Characteristic facial and body features, alongside specific developmental and behavioral patterns, are crucial for diagnosis.
- The genetic basis of FHS does not appear to involve large-scale copy-number variations in the studied cohort.
Abstract:
Floating-Harbor syndrome (FHS) is a rare condition typified by short stature, speech impairment, delayed bone age, and characteristic facies. The diagnosis can be difficult as the facial changes are subtle in infancy, and the features of short stature, delayed speech, and delayed bone age are frequently encountered in clinical practice. We refine the phenotype in FHS by reporting clinical findings in 10 typically affected individuals ranging in age from 7 to 34 years and present a mother and daughter who display some features of FHS. Bone age measurements were delayed when measured from age 6 months to 6 years but in some patients were normal between 6 and 12 years. Dysmorphic features at different ages are characterized. The lateral profile of the face and the characteristic body habitus aided diagnosis. Significant behavioral problems of hyperactivity, short attention span and aggression during childhood were reported for most individuals. The children studied had a severe and incapacitating disorder of speech and language. Intellectual functioning ranged from borderline normal to moderate intellectual disability. Early puberty was noted. Adult heights were 140-155 cm. Microarray analysis in eight of the patients provided no evidence that FHS is caused by a large-scale copy-number genomic change.
