A patient with de Morsier and Duane syndromes

Septo-optic dysplasia and other midline defects: the role of transcription factors: HESX1 and beyond

Septo-optic dysplasia (SOD) is a highly heterogeneous condition comprising variable phenotypes including midline and forebrain abnormalities, optic nerve and pituitary hypoplasia. Most instances of SOD are sporadic and several aetiologies including drug and alcohol abuse have been suggested to account for the pathogenesis of the condition. However, a number of familial cases have been described with an increasing number of mutations in developmental transcription factors including HESX1, SOX2, SOX3 and OTX2 being implicated in its aetiology. These factors are essential for normal forebrain/pituitary development, and disruptions to these genes could account for the features observed in SOD and other midline disorders. The variable phenotypes observed within the condition are most likely due to the varying contributions of genetic and environmental factors. This review will discuss the current knowledge about SOD. Further study of these and other novel factors may shed light on the complex aetiology of this condition.

Bilateral Duane retraction syndrome with optic nerve hypoplasia

The authors report a unique case of a child with the infrequent association of bilateral Duane retraction syndrome with underdevelopment of the anterior visual pathway. Both conditions were caused presumably due to a common disturbance of neuronal development during the second month of embryogenesis.

Septo-optic dysplasia with bilateral congenital corneal anesthesia

Septo-optic dysplasia, or de Morsier syndrome, is characterized by optic nerve hypoplasia with an absent septum pellucidum and/or pituitary abnormalities. Congenital corneal anesthesia is a rare disorder that has been associated with many neurological disorders. Here we present a patient with both conditions who was successfully treated with permanent lateral tarsorrhaphy and aggressive lubrication. To our knowledge, congenital corneal anesthesia has not been reported in association with septo-optic dysplasia. The purpose of this report is to make pediatric ophthalmologists aware of a potential association since the diagnosis of congenital corneal anesthesia is often difficult and delayed.

Phenotypic variability in children with growth hormone deficiency associated with posterior pituitary ectopia

OBJECTIVE

The cause of posterior pituitary ectopia (PPE) with anterior pituitary hormone deficiencies is unknown. This disease is usually considered sporadic. The objective of this study was to improve the phenotypic characterization of children with PPE and growth hormone deficiency (GHD) to seek insight into the mechanisms underlying abnormal pituitary-gland development.

PATIENTS AND DESIGN

Sixty children with GHD and PPE were evaluated in this retrospective chart review (1988-2003).

RESULTS

Known extra-pituitary birth defects (BD) were present in 31 patients (BD+, 52%) and absent in 29 patients (BD-). Among BD+ patients, seven had well-defined syndromes (Fanconi anaemia, n = 2; Pallister-Hall, n = 1; Currarino, n = 2; or Stilling-Duane, n = 2) and the other 24 had 53 BDs, mainly involving the brain, eyes and the craniofacial structures (n = 27, 51%) but also affecting the heart, skeleton, kidneys, gastrointestinal tract and skin. Of the 60 patients, seven (12%) were born to consanguineous parents (five sporadic and two familial cases). There were seven (12%) familial cases, with wide variations in clinical presentation, endocrine profiles and magnetic resonance imaging (MRI) findings within families and various patterns consistent with autosomal dominant, recessive or X-linked transmission.

CONCLUSION

The high rate of extra-pituitary BDs and of familial components supports a role for genetic factors in the pathogenesis of this heterogeneous disorder. A detailed record of phenotypic abnormalities in patients with GHD and PPE might produce useful hypotheses for genetic studies.