Ramos-Arroyo Syndrome

Ramos-Arroyo syndrome (RAS) is a very rare genetic disorder characterized by corneal anesthesia, retinal abnormalities, bilateral hearing loss, distinct facies, patent ductus arteriosus, Hirschsprung disease (see these terms), short stature, and intellectual disability.

Epidemiology

Prevalence and incidence are not known. RAS is extremely rare with only six cases reported to date.

Clinical description

The phenotype in RAS is variable. Some affected individuals have only mild disease manifestations. Characteristic features include corneal anesthesia, nasolacrimal duct obstruction, absent peripapillary choriocapillaris and retinal pigment epithelium, poor visual acuity, and moderate to severe sensorineural deafness. Developmental delay and intellectual disability are common. Patent ductus arteriosus, Hirschsprung disease, and short stature have also been observed. Affected individuals have a distinct facial appearance with a broad face, prominent forehead, hypertelorism, upslanting palpebral fissures, concave nasal ridge, and underdeveloped midface. Feeding problems and failure to thrive are common in infancy. Challenging behavior has been reported in two cases. Overlap with the group of diseases known as hereditary sensory and autonomic neuropathy (HSAN, see this term) has been suggested.

Etiology

The etiology of this syndrome is not yet known. Mutations in an as of yet unidentified gene, involved in autonomic nervous system function, are suspected.

Genetic counseling

RAS follows an autosomal dominant pattern of inheritance, probably with variable expressivity.