The association of optic nerve hypoplasia and deficiency of the septum 
pellucidum and hypopituitarism is known as the De Morsier syndrome or 
septo-optic dysplasia. Four children with blindness and growth retardation due 
to growth hormone deficiency are described. Frequent recurrent episodes of 
severe hypoglycaemia, starting in the newborn period, were observed in three of 
them. Although visual impairment was noted during the first year and growth 
failure was detected between the first and sixth year of life in all four 
patients, the diagnosis of septo-optic dysplasia was delayed for two to six 
years. Early diagnosis and treatment with growth hormone should prevent attacks 
of hypoglycaemia and their sequelae and bring about normal growth.