Journal of Pediatric Neurosciences
: 2009  |  Volume : 4  |  Issue : 1  |  Page : 49-

Septo-optic dysplasia with olfactory tract hypoplasia

Manuel Ribeiro1, Alvaro Machado2, Joao Soares-Fernandes1,  
1 Department of Neuradiology , Hospital de S�o Marcos, Braga, Portugal
2 Department of Neurology, Hospital de S�o Marcos, Braga, Portugal

Correspondence Address:
Alvaro Machado
Hospital de S�o Marcos Largo Carlos Amarante Ap 4200 Braga

How to cite this article:
Ribeiro M, Machado A, Soares-Fernandes J. Septo-optic dysplasia with olfactory tract hypoplasia.J Pediatr Neurosci 2009;4:49-49

How to cite this URL:
Ribeiro M, Machado A, Soares-Fernandes J. Septo-optic dysplasia with olfactory tract hypoplasia. J Pediatr Neurosci [serial online] 2009 [cited 2023 Jun 3 ];4:49-49
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Full Text


Septo-optic dysplasia (SOD) is a rare developmental anomaly, characterized by optic nerve hypoplasia and septum pellucidum (SP) agenesis, which is frequently associated with hormonal deficiencies. [1] The combination of SOD and olfactory tract hypoplasia is very rare. We present here one such case of a four month-old male patient with the antenatal diagnosis of an SP cyst.

The child had an otherwise unremarkable birth history and physical development, having appropriately reached all early childhood milestones. Transfontanelar ultrasonographic examination revealed absence of SP and mild enlargement of the lateral ventricles. MRI [Figure 1] confirmed complete SP absence and showed right optic nerve atrophy. Hypoplasia of the olfactory tract and sulci hypoplasia were also noted. There was diffuse white matter atrophy with thinning of the corpus callosum which was otherwise well formed, and large ventricles with squared-off appearance of the frontal horns. The pituitary gland was small and there was no evidence of schizencephaly. Ophthalmologic examination confirmed right optic disc hypoplasia whereas endocrine studies showed no abnormalities.

The diagnosis of SOD is established when optic disc hypoplasia is observed in association with agenesis of the septum pellucidum. [1],[2] This case represents a very rare association of SOD and olfactory tract hypoplasia.

The etiology of SOD remains uncertain, with genetic abnormalities (in continuum with lobar holoprosencephaly) and intrauterine insults having nevertheless been proposed as etiological factors. [1] In several cases, mutations in the HESX1 gene were shown to be implicated with mild pituitary hypoplasia or SOD. [1] Transgenic mice lacking the homolog gene of human Hesx1 exhibit a phenotype, including SP abnormalities, hypoplastic optic vesicles, pituitary dysplasia, and defective olfactory development. [3] SOD also presents a highly variable phenotype in humans. [2] The authors believe that bulb and tract olfactory hypoplasia should be included in the variable phenotype of SOD.


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3Dattani MT, Martinez-Barbera JP, Thomas PQ, Brickman JM, Gupta R, Wales JK, et al . HESX1: A novel gene implicated in a familial form of septo-optic dysplasia. Acta Paediatr Suppl 1999;88:49-54.