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Disease Profile

Floating-Harbor syndrome

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

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US Estimated

Europe Estimated

Age of onset

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ICD-10

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Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Short stature with delayed bone age, expressive language delay, a triangular face with a prominent nose and deep-set eyes; Pelletier-Leisti syndrome; FHS

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

Floating-Harbor syndrome (FHS) is named after the two hospitals that reported the first cases in the 1970s: Boston Floating Hospital and Harbor General Hospital in California.[1] Signs and symptoms of FHS include short stature, skeletal abnormalities, delayed bone age, kidney problems, minor problems with hearing and vision, characteristic facial features, speech and language problems, and mild to moderate intellectual disabilities.[1][2][3][4][5] Behavioral difficulties that are present in many children tend to improve with age.[4] FHS is caused by a change (mutation) in the SRCAP gene and inheritance is autosomal dominant. The mutation can be inherited from a parent or can occur for the first time in a person with the syndrome.[1][3][4] Communication issues and developmental disabilities may be helped with early intervention programs and special education.[4]

Symptoms

The specific symptoms and severity of Floating-Harbor syndrome (FHS) can vary from person to person. Signs and symptoms that have been reported in people with FHS include:[1][3][4][5][6][7][8]

  • Short stature and slowing of the mineralization of bones (delayed bone age). Bone age is delayed in early childhood and usually becomes normal between ages 6 and 12. 
  • Speech and language delays.
  • Mild to moderate intellectual disability.
  • Hearing or vision problems.
  • Characteristic facial features which may include a prominent nose, triangular face, low hairline, deep set eyes, long eyelashes, and a shortened distance between the nose and upper lip (short philtrum). Some facial features may become more apparent over time.
  • Kidney problems such as hydronephrosis, kidney cysts, or having one kidney.
  • Gastrointestinal problems such as reflux and constipation.
  • Minor genital problems such as undescended testes or hypospadias (when the opening of the penis is not located on the tip).
  • Various skeletal abnormalities including such as short fingers (brachydactyly), large or bulging fingertips (clubbing), bent or curved fingers (clinodactyly), short or broad thumbs, prominent joints, abnormalities of the collarbone, craniosynostosis, and Perthes disease (a condition that occurs when the blood supply to the head of the thigh bone is temporarily disrupted).
  • Dental problems such as delays in losing baby teeth, and having small teeth.
  • Behavior and temperament difficulties that tend to improve in adulthood.
  • Seizures.

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Cause

FHS is caused by mutations in the SRCAP gene. The mutation can be inherited from a parent or it can be the result of a new mutation in the affected individual. FHS is passed on in an autosomal dominant manner which means each child of parent with a mutation has a 50% chance of also having the mutation.[1][4]

Treatment

The treatment of FHS is directed toward specific symptoms. Early intervention and services are important to insure that children with FHS reach their potential. Treatment may require the coordinated effort of a team of specialists, including: pediatricians, neurologists, orthopedists, audiologists, ophthalmologists, occupational therapists, physical therapists, and speech therapists.[3][4]

Additional social and vocational services may also help. In some cases, behavior management strategies may be needed.[3][4] Yearly testing of vision, hearing, blood pressure, and kidney function are suggested. Ultrasound imaging to check for kidney (renal) cysts in affected teenagers and adults is also suggested.[4]

Growth hormone has been used to treat some individuals with FHS, although information about its effectiveness in this population is limited.[3][4] 

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Broad columella
0010761
Broad thumb
Broad thumbs
Wide/broad thumb

[ more ]

 0011304
Bulbous nose
0000414
Delayed skeletal maturation
Delayed bone maturation
Delayed skeletal development

[ more ]

 0002750
Expressive language delay
0002474
High pitched voice
0001620
Joint stiffness
Stiff joint
Stiff joints

[ more ]

 0001387
Long eyelashes
Increased length of eyelashes
Unusually long eyelashes

[ more ]

 0000527
Nasal speech
Nasal voice
0001611
Neurological speech impairment
Speech disorder
Speech impairment
Speech impediment

[ more ]

 0002167
Posteriorly rotated ears
Ears rotated toward back of head
0000358
Prominent nose
Big nose
Disproportionately large nose
Increased nasal size
Increased size of nose
Large nose
Pronounced nose

[ more ]

 0000448
Short neck
Decreased length of neck
0000470
Short philtrum
0000322
Short stature
Decreased body height
Small stature

[ more ]

 0004322
Thin vermilion border
Decreased volume of lip
Thin lips

[ more ]

 0000233
Wide mouth
Broad mouth
Large mouth

[ more ]

 0000154
Wide nasal bridge
Broad nasal bridge
Broad nasal root
Broadened nasal bridge
Increased breadth of bridge of nose
Increased breadth of nasal bridge
Increased width of bridge of nose
Increased width of nasal bridge
Nasal bridge broad
Wide bridge of nose
Widened nasal bridge

[ more ]

 0000431
30%-79% of people have these symptoms
Abnormal soft palate morphology
0100736
Brachydactyly
Short fingers or toes
0001156
Camptodactyly of finger
Permanent flexion of the finger
0100490
Clinodactyly of the 5th finger
Permanent curving of the pinkie finger
0004209
Congenital pseudoarthrosis of the clavicle
0006585
Constipation
0002019
Deeply set eye
Deep set eye
Deep-set eyes
Sunken eye

[ more ]

 0000490
Enlarged joints
0003037
Feeding difficulties in infancy
0008872
Generalized hirsutism
Excessive hairiness over body
0002230
Global developmental delay
0001263
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

 0001249
Intrauterine growth retardation
Prenatal growth deficiency
Prenatal growth retardation

[ more ]

 0001511
Joint hyperflexibility
Joints move beyond expected range of motion
0005692
Malabsorption
Intestinal malabsorption
0002024
Recurrent otitis media
Recurrent middle ear infection
0000403
Short clavicles
Short collarbone
0000894
Triangular face
Face with broad temples and narrow chin
Triangular facial shape

[ more ]

 0000325
Underdeveloped nasal alae
Underdeveloped tissue around nostril
0000430
5%-29% of people have these symptoms
Abnormal fingernail morphology
Abnormal fingernails
Abnormality of the fingernails

[ more ]

 0001231
Abnormality of cardiovascular system morphology
0030680
Atrial septal defect
An opening in the wall separating the top two chambers of the heart
Hole in heart wall separating two upper heart chambers

[ more ]

 0001631
Coarctation of aorta
Narrowing of aorta
Narrowing of the aorta

[ more ]

 0001680
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment

[ more ]

 0100543
Conductive hearing impairment
Conductive deafness
Conductive hearing loss

[ more ]

 0000405
Congenital posterior urethral valve
0010957
Cryptorchidism
Undescended testes
Undescended testis

[ more ]

 0000028
Epididymal cyst
0030424
Generalized cerebral atrophy/hypoplasia
Generalized cerebral degeneration/underdevelopment
0007058
Hydronephrosis
0000126
Hypermetropia
Farsightedness
Long-sightedness

[ more ]

 0000540
Hypoplasia of penis
Underdeveloped penis
0008736
Hypospadias
0000047
Conditions with similar signs and symptoms from Orphanet
The differential diagnosis should include other dysmorphic syndromes, in particular Rubinstein-Taybi syndrome.
Visit the Orphanet disease page for more information.

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • Genetics Home Reference (GHR) contains information on Floating-Harbor syndrome. This website is maintained by the National Library of Medicine.
    • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
    • Unique is a source of information and support for families and individuals affected by rare chromosome disorders. Click on the link to view information about Floating-Harbor syndrome.

      In-Depth Information

      • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Floating-Harbor syndrome. Click on the link to view a sample search on this topic.

        References

        1. Floating-Harbor syndrome. Genetics Home Reference. December, 2012; https://ghr.nlm.nih.gov/condition/floating-harbor-syndrome#genes.
        2. Floating Harbor Syndrome Support Group. https://www.floatingharborsyndromesupport.com/. Accessed 4/29/2016.
        3. Nikkel, Sarah. Floating Harbor Syndrome. National Organization for Rare Disorders (NORD). 2014; https://rarediseases.org/rare-diseases/floating-harbor-syndrome.
        4. Nowaczyk, Malgorzata. Floating-Harbor syndrome. GeneReviews. January, 2013; https://www.ncbi.nlm.nih.gov/books/NBK114458.
        5. Floating-Harbor syndrome. Unique. 2016; https://www.rarechromo.org/media/singlegeneinfo/Single%20Gene%20Disorder%20Guides/Floating-Harbor%20syndrome%20FTNW.pdf.
        6. Messina G, Atterrato MT, Dimitri P. When chromatin organisation floats astray: the Srcap gene and Floating–Harbor syndrome. J Med Genet. December, 2016; 53(12):793-797. https://www.ncbi.nlm.nih.gov/pubmed/27208210.
        7. Milani D, Scuvera G, Gatti M, Tolva G, Bonarrigo F, Esposito S, Gervasini C. Perthes disease: A new finding in Floating-Harbor syndrome. Am J Med Genet A. March, 2018; 176(3):703-706. https://www.ncbi.nlm.nih.gov/pubmed/29383823.
        8. FLOATING-HARBOR SYNDROME; FLHS. Online Mendelian Inheritance in Man (OMIM). August 21, 2014; https://www.omim.org/entry/136140.

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