Floating Harbor Syndrome

Floating Harbor Syndrome

National Organization for Rare Disorders, Inc.


It is possible that the main title of the report Floating Harbor Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • FHS
  • Pelletier-Leisti syndrome

Disorder Subdivisions

  • None

General Discussion

Floating-Harbor syndrome (FHS) is an extremely rare disorder characterized by short stature, delayed language skills, and a triangular shaped face. A broad nose, deep-set eyes and a wide mouth with thin lips give an affected individual a distinct appearance. FHS was named after the hospitals at which the first two cases were seen: the Boston Floating Hospital and Harbor General Hospital in California. The cause of this disorder is not known.


Individuals with Floating-Harbor syndrome develop short stature with delayed bone growth, a delay in expressive language, and distinct facial features.

In some cases, delayed growth may occur before birth (prenatal growth retardation) resulting in low birth weight. Typically, growth deficiencies become apparent during the first year of life. Affected children develop short stature, usually below the 5th percentile. In addition to growth deficiencies, all children with FHS have a delay in bone aging, which means that the rate of growth and development of the bones is slower than normal. The limbs and trunk are in proportion, while the head may appear relatively large.

Delay in the acquisition of expressive language is found in all children with FHS. Some children may be delayed in their learning ability as well. Most children appear to be slightly behind in school but there have been no recorded cases of severe or even moderate retardation.

Distinctive facial features are another symptom of FHS. These features typically become apparent at the age of three or four years. The nose and nasal bridge are broad, and the mouth is wide with thin lips. The eyes are deeply set and the face appears small with a triangular shape. Eyelashes may be longer than normal, and there may be dental abnormalities.

Additional symptoms may be associated in some cases of FHS. These symptoms do not occur in all cases. Abnormal bending (clinodactyly) of the fifth finger, abnormally short fingers (brachydactyly), clubbing of the fingers and/or excessive body hair (hirsutism) have been found in some individuals with FHS.

An intestinal malabsorption disorder caused by intolerance to gluten (celiac sprue) has been found in several individuals with this disorder. (For more information on this disorder, choose "Celiac Sprue" as your search term in the Rare Disease Database).

An additional thumb, constipation and/or a narrowing of the opening of the right ventricle into the pulmonary artery (pulmonary stenosis) have also been found in several affected individuals. Abnormal placement of the urinary opening on the underside of the penis (hyposapdias), a distinct, high-pitched voice, a malformed (dysplastic) hip, and clouding of the lenses of the eyes (cataracts) may also occur.


The exact cause of Floating-Harbor syndrome is not known. Both males and females are affected. There have been no reported cases of recurrence within a family. It is thought that FHS may be a new dominant mutation. A mutation is an unusual change in genetic material that has occurred for no apparent reason (sporadically). The alteration changes the original expression of the gene. When a mutation occurs, it can be transmitted to future generations.

Affected Populations

Floating-Harbor syndrome is an extremely rare disorder that affects males and females in equal numbers. There have been approximately 20 cases of this disorder reported in the medical literature. It is thought that the incidence of this disorder may actually be higher because many cases go unrecognized.

FHS was first described in the medical literature in 1973.

Standard Therapies

A diagnosis of Floating-Harbor syndrome may be made based upon a detailed clinical evaluation, a detailed patient history and identification of characteristic findings. X-ray studies (radiography) may reveal delayed bone age.

There is no specific treatment for FHS. Affected children will benefit from an educational environment that provides appropriate programs to assist their needs. Speech therapy as well as teachers trained to work with learning disabilities are beneficial.

Other treatment is symptomatic and supportive. Genetic counseling may be of benefit for affected individuals and their families.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222

TTY: (866) 411-1010

Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:




Lubinsky MS. Floating Harbor Syndrome. In: NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:195.

Thoene JG, ed. Physicians' Guide to Rare Diseases. Montvale, NJ: Dowden Publishing Company Inc; 1995:72-73.


De Benedetto MS, et al. Floating-Harbor syndrome: case report and craniofacial phenotype characterization. Int J Paediatr Dent. 2004;14:208-13.

Selimoglu MA, et al. First Turkish patient with Floating-Harbor syndrome with additional findings: cryptorchidism and microcephaly. Yonsei Med J. 2004;45:334-6.

Ioan D, Fryns JP. Floating-Harbor syndrome in two sisters: autosomal recessive inheritance or germinal mosaicism? Genet Couns. 2003;14:431-3.

Rosen AC, et al. A further report on a case of Floating-Harbor Syndrome in a mother and daughter. J Clin Exp Neuropsychol. 1998;20:483-95.

Hersh JH, et al. Changing phenotype in Floating-Harbor syndrome. Am J Med Genet. 1998;76:58-61.

Midro AT, et al. Floating Harbor syndrome. Case report and further syndrome delineation. Ann Genet. 1997;40:133-38.

Fryns JP, et al. The Floating-Harbor syndrome: two affected siblings in a family. Clin Genet. 1996;50:217-19.

Davalos IP, et al. Floating-Harbor syndrome. A neuropsychological approach. Genet Couns. 1996;7:283-88.

Smeets E, et al. The Floating-Harbor syndrome: report of another patient and differential diagnosis with Shprintzen syndrome. Genet Couns. 1996;7:143-46.

Lazebnik N, et al. The floating harbor syndrome with cardiac septal defect. Am J Med Genet. 1996;66:300-02.


McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore. MD: The Johns Hopkins University; Entry No: 136140; Last Update:6/17/1998.


Human Growth Foundation

997 Glen Cove Avenue

Suite 5

Glen Head, NY 11545

Tel: (516)671-4041

Fax: (516)671-4055

Tel: (800)451-6434

Email: hgf1@hgfound.org

Internet: http://www.hgfound.org/

Restricted Growth Association

PO Box 5137

Yeovil, BA20 9FF

United Kingdom

Tel: 03001111970

Fax: 03001112454

Email: office@restrictedgrowth.co.uk

Internet: http://www.restrictedgrowth.co.uk

NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases

Information Clearinghouse

One AMS Circle

Bethesda, MD 20892-3675


Tel: (301)495-4484

Fax: (301)718-6366

Tel: (877)226-4267

TDD: (301)565-2966

Email: NIAMSinfo@mail.nih.gov

Internet: http://www.niams.nih.gov/

Floating Harbor Syndrome Support Group

1964 Sheffield Road

Harmony, NC 28634


Tel: (336)831-6955

Email: littleflock7@gmail.com

Internet: http://www.floatingharborsyndromesupport.com

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126

Gaithersburg, MD 20898-8126

Tel: (301)251-4925

Fax: (301)251-4911

Tel: (888)205-2311

TDD: (888)205-3223

Internet: http://rarediseases.info.nih.gov/GARD/

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into myCigna.com. For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html.

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