Although researchers have been able to establish a syndrome with characteristic or “core” symptoms, much about the disorder is not fully understood. Several factors including the small number of identified cases, the lack of large clinical studies, and the possibility of other genes influencing the disorder prevent physicians from developing a complete picture of associated symptoms and prognosis.
In all cases reported in the medical literature, affected individuals have exhibited mild to severe intellectual disability. Individuals with Fountain syndrome may also exhibit several physical abnormalities. For example, fluid may abnormally accumulate under the skin (edema) of the face, especially the lips and cheeks. As a result, the face may appear coarse, abnormally “full,” and swollen. These distinctive facial characteristics may be more pronounced with age.
Fountain syndrome may also be characterized by Deafness at birth (congenital deafness) due to a defect in a bony spiral organ in the inner ear (cochlea). In this type of deafness, although sound is transmitted normally through the external and middle ear, the cochlear malformation in the inner ear causes the Hearing loss (congenital sensorineural deafness). The cochlea normally transforms sound vibrations into nerve impulses that are transmitted to the brain. Because congenital sensorineural Deafness results in an inability to hear spoken language, affected infants and children may be unable to develop and comprehend verbal language structure, resulting in an inability to communicate through speech (deaf mutism).
Individuals with Fountain syndrome may also have Skeletal abnormalities including abnormal thickening of the cap of the skull (calvaria) and/or unusually broad, short, and stubby hands and feet. In addition, in some cases, affected individuals may exhibit extreme front-to-back curvature of the spine (hyperkyphosis) and/or short stature.
In some cases, individuals with Fountain syndrome may exhibit additional physical abnormalities. For example, during infancy, some individuals may experience episodes of repeated, uncontrolled electrical disturbances involving both sides of the brain (generalized seizures), be below average height for their age (short stature), an abnormally Large head circumference (macrocephaly), and broad, plump hands.