Septo-optic nerve dysplasia is a rare congenital anomaly known to be caused by a midline developmental defect in the prosencephalon. The clinical findings are visual impairment, hypopituitarism and developmental delays and severity is related to the extent of the cerebral anomalies in septum pellucidum, optic nerves and hypothalamus. The aim of this study was to report prevalence, associated anomalies, maternal age and other epidemiology factors from a large European population based network of congenital anomaly registries (EUROCAT). Data from 29 full member registries for the years 2005-2014 were included, covering 6.4 million births. There were 99 cases with a diagnosis of septo-optic dysplasia. There was evidence of under-reporting in some registries. If underreporting was assumed to occur in the 14 registries with the lowest prevalences, the overall prevalence in the top 15 registries would be a good estimate of the overall prevalence. It was 2.51 per 100,000 births (95%CI: 1.60-3.58), with clear evidence of heterogeneity; I2=59.9%. If there was no under-reporting the estimated prevalence for all registries would be 2.51/1.35 = 1.9 per 100,000 births with 95% CI approximately (1.2 - 2.6) (The 1.35 adjusts for taking the prevalence of the highest 15 registries). The prevalence of septo-optic dysplasia in Europe is therefore likely to be between 1.9 to 2.5 per 100,000 births. The prevalence was highest for mothers aged 20 to 24 years of age and was significantly higher in UK registries compared with other EUROCAT registries (P = 0.021 in the multilevel model) and the increase was greater for younger mothers in the UK (P=0.027). The majority of septo-optic dysplasia cases were classified as isolated cerebral anomaly (77%) and only two cases had a genetic diagnosis. The anomaly may not be apparent at birth and this is reflected in that 57% of the postnatal diagnoses occurred over 1 month after birth.
Septo-optic dysplasia share patterns with gastroschisis and this strengthen the hypothesis of vascular disruption being an aetiological factor for septo-optic dysplasia.JRC.F.1-Health in Societ
