SNP Shot: Genomic Insights

Floating-Harbor syndrome is a rare condition characterized by short stature, delayed bone development (delayed bone age), speech delays, and distinctive facial features. The name "Floating-Harbor" originates from the Boston Floating Hospital and Harbor General Hospital in Torrance, California, where the syndrome was initially identified.

Individuals with Floating-Harbor syndrome typically exhibit growth deficiency starting in their first year. They generally fall within the shortest 5% of individuals in their age group. Bone age is often delayed in early childhood, with a 3-year-old potentially having bones resembling those of a 2-year-old. However, bone age usually normalizes between 6 and 12 years of age.

Expressive language delay, or difficulty in speech development, can be significant in Floating-Harbor syndrome, impacting verbal communication skills. Mild intellectual disability is also commonly observed. Motor skill development, such as sitting and crawling, usually progresses at a typical pace.

The characteristic facial features associated with Floating-Harbor syndrome include a triangular face, a low hairline, deep-set eyes, long eyelashes, a prominent nose with an overhanging columella (the tissue separating the nostrils), a short philtrum (the area between the nose and upper lip), and thin lips. The nose tends to become more prominent as the child matures.

Some individuals with Floating-Harbor syndrome may also have finger abnormalities such as short fingers (brachydactyly), rounded fingertips (clubbing), and curved pinky fingers (fifth finger clinodactyly). Other potential features include a high-pitched voice and, in males, undescended testicles (cryptorchidism).

Inheritance:

Floating-Harbor syndrome follows an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene is needed in each cell to cause the condition. Most cases arise from new, spontaneous mutations in the gene, occurring in individuals with no family history of the syndrome. However, in some instances, an affected person inherits the mutation from a parent who also has the condition.