Septo-optic dysplasia with amniotic band syndrome sequence: a case report.

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.

FEVR phenotype associated with septo-optic dysplasia.

Background: Septo-optic dysplasia, also known as de Morsier syndrome, is a disorder of brain development characterized by optic nerve hypoplasia, hypopituitarism, and midline brain defects.Materials and Methods: Single retrospective case report.Results: An infant born at 38 5/7 weeks gestation age weighing 3125 g developed respiratory distress shortly after birth. Systemic findings included myocardial dysfunction, hypopituitarism, feeding intolerance, microphallus, and dysmorphic features. Eye examination revealed tractional retinal detachments and optic nerve hypoplasia. In addition, peripheral non-perfusion and peripheral neovascularization were consistent with Familial Exudative Vitreoretinopathy (FEVR) phenotype. MRI showed hypoplastic optic nerves, ectopic posterior pituitary with hypoplastic pituitary infundibulum, and slightly thin corpus callosum, diagnostic of septo-optic dysplasia. Genetic testing revealed no pathogenic variants and two variants of uncertain significance.Conclusion: FEVR findings can be associated with septo-optic dysplasia and may point to an etiologic connection between neural development and subsequent vascular development.

Incidental discovery of subtle-variant septooptic dysplasia in an adult with headaches: a novel case with pathophysiologic implications.

Septooptic dysplasia (SOD) is a congenital central nervous system malformation syndrome classically associated with the triad of agenesis of the septum pellucidum, optic nerve hypoplasia, and pituitary abnormalities. It has been suggested that SOD may result from in utero vascular insults. We present the case of an adult male with personal and family histories of intracranial vascular pathology in whom SOD was incidentally discovered, and we describe how the specific abnormalities in this case could be related to vascular pathology.

Septo-optic dysplasia: antenatal risk factors and clinical features in a regional study.

BACKGROUND: Septo-optic dysplasia (SOD) is a disorder with postulated environmental and genetic aetiology. This study delineates clinical features and potential perinatal environmental factors along with epidemiology in SOD children. METHODS: Assessment of patients with SOD triad features in the UK West Midlands region. RESULTS: Of 227 patients identified between 1998 and 2009 with 1 or more feature of the triad, 55 had midline defects, 149 had optic nerve hypoplasia and 132 had hypopituitarism. Eighty-eight children (52% males; incidence 8.3/100,000 live births) had SOD defined as 2 out of 3 features and 21 (24%) had all 3. Sixty-one percent had anterior pituitary deficiency and 21.5% had diabetes insipidus. Median maternal/paternal ages in SOD were 21 and 23.5 years, compared to UK means of 29.3 and 32.4 years (p < 0.001). First trimester bleeding was markedly increased at 12/48 (25%) compared to 0.07% in the UK (p < 0.001). Ethnicity showed a non-significant higher prevalence in Afro-Caribbean and mixed race groups, and significantly lower prevalence (p = 0.004) in South Asian groups compared to West Midland and Birmingham city data: 8% versus 2.5 and 6.7%, 9% versus 1.8 and 3.2% and 3% versus 8.4 and 21%, respectively. CONCLUSIONS: SOD is associated with younger maternal and paternal age, primigravida births and ethnic differences. Increased first trimester bleeding may indicate that SOD is a vascular disruption sequence.

Septo-optic dysplasia - novel insights into the aetiology.

Septo-optic dysplasia (SOD) is a highly heterogeneous condition comprising a variable phenotype of optic nerve hypoplasia, midline brain abnormalities and pituitary hypoplasia with consequent endocrine deficits. The majority of cases are sporadic and several aetiologies have been suggested to account for the pathogenesis of the condition. However, a number of familial cases have been described and the identification of mutations in key developmental genes including HESX1, SOX2 and SOX3 in patients with SOD and associated phenotypes suggests that a genetic causation is likely in the more common sporadic cases of the condition. The precise aetiology of SOD is most likely multifactorial involving contributions from environmental factors in addition to an important role for crucial developmental genes. The variability of the penetrance and phenotypes within a single SOD pedigree may also suggest a complex interaction between genetics and the environment, and at present, the understanding of these interactions is rudimentary. Further study of these critical factors may shed light on the aetiology of this complex disorder. We have reviewed recent literature selecting relevant references based on the keywords HESX1, SOX2, SOX3, Septo-optic dysplasia, genetics and pituitary development.

Septo-optic dysplasia associated with abnormal pubertal development.

Septo-optic dysplasia (SOD) is a congenital anomaly, that is characterized by a triad of optic nerve hypoplasia, structural brain defects, and hypothalamic-pituitary dysfunction. This condition is very rare and it has never been reported in a Thai population. In the present report, the authors described two SOD cases that presented with primary amenorrhea and abnormal pubertal development. Clinical features. Possible etiology of this condition was reviewed

Maternal age in patients with septo-optic dysplasia.

AIM: To determine whether patients with septooptic dysplasia (SOD) are of normal birth weight and gestation but are born to mothers who are significantly younger than average. METHODS: Retrospective study of 30 patients with SOD attending the Royal Hospital for Sick Children, Glasgow. Birth data for the Scottish population were used for comparison. RESULTS: Mean birth weight was 3.42 (range 2.66-4.18) kg. One patient was born preterm while the rest were born at term. Data for the Scottish population were available from 1979 onwards and 26 patients born after this year were selected for analysis. Median maternal age in this group was 21 (range 16-41) years, significantly lower than the median maternal age for Scotland of 27.12 (range 25.8-28.6) years (95% CI 4.8-8.0 years). CONCLUSION: Patients with SOD are of normal birth weight and gestation but are born to mothers who are significantly younger than average.

Ganglion cell axon pathfinding in the retina and optic nerve.

The eye is a highly specialized structure that gathers and converts light information into neuronal signals. These signals are relayed along axons of retinal ganglion cells (RGCs) to visual centers in the brain for processing. In this review, we discuss the pathfinding tasks RGC axons face during development and the molecular mechanisms known to be involved. The data at hand support the presence of multiple axon guidance mechanisms concentrically organized around the optic nerve head, each of which appears to involve both growth-promoting and growth-inhibitory guidance molecules. Together, these strategies ensure proper optic nerve formation and establish the anatomical pathway for faithful transmission of information between the retina and the brain.

Septo-optic dysplasia: a literature review.

BACKGROUND: Septo-optic dysplasia (SOD) is a rare disorder characterized by optic nerve hypoplasia with any combination of absent septum pellucidum and/or pituitary dysfunction. SOD may manifest as strabismus, nystagmus, decreased visual acuity, or visual impairment; as an endocrine dysfunction in isolation; or in addition to mental retardation, cerebral palsy, developmental delay, or delayed growth. METHOD: This article reviews the presenting signs and symptoms of SOD, optic nerve hypoplasia, consequences of an absent septum pellucidum, endocrine findings associated with SOD, SOD diagnosis determination, syndromes associated with SOD, and optometry's role in caring for these patients. It also examines two cases that demonstrate the variety and severity of visual and physical impairments associated with SOD. RESULTS: SOD has a multi-factorial etiology, including insult during pregnancy (e.g., viral infections, gestational diabetes); vascular disruption; or a genetic mutation. Children with SOD may manifest a variety of visual and/or physical symptoms that range from mild to severe. CONCLUSIONS: The associated vision, developmental, neurologic, and endocrine disturbances require early diagnosis and management. Optometrists need to be aware of optic nerve hypoplasia (ONH) and consider this diagnosis in patients with visual acuity loss. A comprehensive eye examination and visual-field assessment should be completed in addition to appropriate referrals for endocrine, developmental, and/or cognitive anomalies.

Cerebral midline developmental anomalies: endocrine, neuroradiographic and ophthalmological features.

BACKGROUND: Hypopituitarism may occur in patients with midline cerebral defects (MCD), including septo-optic dysplasia (SOD). HESX1 gene mutations have been associated with SOD. OBJECTIVE: To evaluate the endocrine, ophthalmological and neuroradiographic abnormalities in 18 patients with MCD and SOD without mutations at the HESX1 locus. STUDY DESIGN: The diagnosis of hypothalamic and pituitary abnormalities was confirmed by clinical findings and basal hormone values or functional tests. All patients underwent ophthalmological examination and neuroradiologic studies by MRI. RESULTS: The diagnosis of hypothalamic and pituitary abnormalities varied from 3 days to 13 years. Endocrine abnormalities were found in 88% of the patients: GH deficiency (72%), hypothyroidism (66%), hypogonadism (45%), diabetes insipidus (27%), adrenal insufficiency (10%), and precocious puberty (5%). Psychomotor retardation was observed in 55% and seizures in 22%. Visual status varied from normal to blindness. MRI confirmed heterogeneous intracranial malformations. CONCLUSIONS: Our data support the need for systematic and periodic endocrine evaluation of patients with MCD using a multidisciplinary approach.

Molecular effects of novel mutations in Hesx1/HESX1 associated with human pituitary disorders.

The homeobox gene Hesx1/HESX1 has been implicated in the establishment of anterior pattern in the central nervous system (CNS) in a number of vertebrate species. Its role in pituitary development has been documented through loss-of-function studies in the mouse. A homozygous missense point mutation resulting in a single amino acid substitution, Arg160Cys (R160C), is associated with a heritable form of the human condition of septo-optic dysplasia (SOD). We have examined the phenotype of affected members in this pedigree in more detail and demonstrate for the first time a genetic basis for midline defects associated with an undescended or ectopic posterior pituitary. A similar structural pituitary abnormality was observed in a second patient heterozygous for another mutation in HESX1, Ser170Leu (S170L). Association of S170L with a pituitary phenotype may be a direct consequence of the HESX1 mutation since S170L is also associated with a dominant familial form of pituitary disease. However, a third mutation in HESX1, Asn125Ser (N125S), occurs at a high frequency in the Afro-Caribbean population and may therefore reflect a population-specific polymorphism. To investigate the molecular basis for these clinical phenotypes, we have examined the impact of these mutations on the regulatory functions of HESX1. We show that Hesx1 is a promoter-specific transcriptional repressor with a minimal 36 amino acid repression domain which can mediate promoter-specific repression by suppressing the activity of homeodomain-containing activator proteins. Mutations in HESX1 associated with pituitary disease appear to modulate the DNA-binding affinity of HESX1 rather than its transcriptional activity. Wild-type HESX1 binds a dimeric homeodomain site with high affinity (K(d) 31 nM) whilst HESX1(S170L) binds with a 5-fold lower activity (K(d) 150 nM) and HESX1(R160C) does not bind at all. Although HESX1(R160C) has only been shown to be associated with the SOD phenotype in children homozygous for the mutation, HESX1(R160C) can inhibit DNA binding by wild-type HESX1 both in vitro and in vivo in cell culture. This dominant negative activity of HESX1(R160C) is mediated by the Hesx1 repression domain, supporting the idea that the repression domain is implicated in interactions between homeodomain proteins. Our data suggest a possible molecular paradigm for the dominant inheritance observed in some pituitary disorders.