Floating-Harbor syndrome (FHS) is a rare genetic condition. It usually affects growth, speech and language, bone development, and facial features. Every person with FHS is different, and many have strengths that no checklist captures.
What causes it?
FHS is caused by a change (variant) in one copy of the SRCAP gene. Researchers identified this gene as the cause in 2012.
- Usually not inherited. In most families, the change happened for the first time in the child. Nothing the parents did or didn’t do caused it.
- Can be passed on. A person with FHS has a 50% chance of passing it to each of their children (autosomal dominant inheritance).
- Testing. A genetic test, usually a gene panel or exome sequencing, can confirm the diagnosis. A genetic counselor can explain the results.
Common features
Not everyone has all of these, and how strongly each one shows up varies a lot.
| Area | What families often see |
|---|---|
| Speech & language | Significant delays in expressive language (speaking), sometimes in understanding too. Some people with FHS are nonverbal and communicate with sign, pictures, or devices. |
| Growth | Short stature. Bone age that’s delayed in early childhood. |
| Learning | Learning differences ranging from mild to more significant. Attention and behavior challenges are common. |
| Face | Deep-set eyes, long eyelashes, a prominent nose, a short space between nose and lip, and a thin upper lip. |
| Hands & skeleton | Short fingers, broad fingertips, and other skeletal differences. |
| Other health | Possible hearing loss, vision problems, dental issues, reflux or celiac disease, and kidney or heart differences. |
Care and support
There’s no cure for FHS, but a lot can be done. Many families find these steps helpful:
- Speech and communication therapy started early, including AAC (augmentative and alternative communication) such as sign language, picture boards, or speech-generating devices.
- Regular hearing and vision checks.
- Growth monitoring with an endocrinologist.
- A kidney ultrasound and heart evaluation around the time of diagnosis.
- Dental care, plus screening for celiac disease if symptoms appear.
- An IEP at school that reflects your child’s real needs, not a generic plan. Our advocacy guide can help.
Going deeper
- GeneReviews: Floating-Harbor Syndrome, the detailed clinical summary many doctors use
- MedlinePlus Genetics: Floating-Harbor syndrome
- NORD: Floating-Harbor syndrome
- GARD (NIH Genetic and Rare Diseases Information Center)
Sources: GeneReviews (NCBI); MedlinePlus Genetics; National Organization for Rare Disorders; Hood RL et al., American Journal of Human Genetics, 2012.