RESUMO
INTRODUCTION: De Morsier syndrome, or septo-optic dysplasia, is a rare, heterogeneous, complex condition with a highly variable phenotype. It is characterized by optic nerve hypoplasia, pituitary gland hypoplasia, and midline brain abnormalities, including absence of septum pellucidum and corpus callosum dysgenesis. Diagnosis is made clinically by the presence of any two or more features from the clinical triad. CASE PRESENTATION: We report a case of a premature African newborn male baby born to nonconsanguineous parents who presented to our institution with agenesis of the septum pellucidum, unilateral optic nerve hypoplasia, and pituitary stalk hypoplasia. However, he had intact central endocrine function. He also presented with limb defects due to constricting amniotic band syndrome. Other dysmorphic features were low-set ears, microcephaly, and bilateral talipes equinovarus. He otherwise had a normal neurological examination result. Over time, he had an adequate weight gain and was managed by a multidisciplinary team. CONCLUSION: De Morsier syndrome still represents a diagnostic challenge, despite advances in neuroimaging and genetic studies, due to the heterogeneous nature of the disorder. This case adds to existing knowledge on the vascular pathogenesis of septo-optic dysplasia.