Floating-Harbor syndrome is a rare autosomal dominant
genetic disorder associated with SRCAP mutation. To date, approximately 50 cases of
Floating-Harbor syndrome have been reported, but none have been reported in Korea yet.
Floating-Harbor syndrome is characterized by delayed bony maturation, unique facial features, and language impairment. Here, we present a 6-year-old boy with a triangular face, deep-set protruding eyes, low-set ears, wide nose with narrow nasal bridge, short philtrum, long thin lips, clinodactyly, and developmental delay that was transferred to our pediatric clinic for genetic evaluation. He showed progressive delay in the area of language and cognition-adaption as he grew. He had previously undergone chromosomal analysis at another hospital due to his
language delay, but his karyotype was normal. We performed targeted exome sequencing, considering several syndromes with similar phenotypes. Library preparation was performed with the TruSight One sequencing panel, which enriches the sample for about 4,800 genes of clinical relevance. Massively parallel sequencing was conducted with NextSeq. An identified variant was confirmed by Sanger sequencing of the patient and his parents. Finally, the patient was confirmed as the first Korean case of
Floating-Harbor syndrome with a novel SRCAP (Snf2 related CREBBP activator
protein) mutation (c.7732dupT, p.Ser2578Phefs*6), resulting in early termination of the
protein; it was not found in either of his healthy parents or a control population. To our knowledge, this is the first study to describe a boy with
Floating-Harbor syndrome with a novel SRCAP mutation diagnosed by targeted exome sequencing in Korea.