Clinical manifestations of 11 children with fronto-ocular syndrome (FOS): a case series

Abstract

Fronto-ocular syndrome (FOS) is a rarely seen trigonocephaly syndrome in which metopic synostosis features are unique. This report presents six cases with FOS. Clinical manifestations mainly involve skull and facial findings. Nearly all patients have short/upslanted palpebral fissures, hypotelorism, narrow bifrontal area, philtrum anomalies, trigonocephaly, and metopic ridge. Epicanthal folds, hypoplastic supraorbital ridges, bulbous nasal tip, thin upper lip, mandible, and ear anomalies are also frequently observed in the patients. Extrafacial findings are variable such as cardiac, extremity anomalies, and skin findings. Mild developmental delay and learning disability have been presented in almost half of patients. Age-dependent and age-independent phenotypic differences between the patients have been detected. Furthermore, it is observed the individuals with reduced phenotypic expression even in the same family. FOS has been described in two families in the literature which consist of mother-daughter dual. Thereby, its inheritance pattern and clinical spectrum have not been clarified clearly. We present here eleven patients that five of them had previously reported. We aim was to give a more comprehensive description of the clinical findings of fronto-ocular syndrome and to reveal its inheritance pattern.