Septo-Optic Dysplasia (De Morsier's Syndrome)
What is Septo-Optic Dysplasia?
Septo-optic dysplasia is a rare congenital condition characterised by the presence of at least two of the following three symptoms: abnormalities affecting the pituitary glands, midline brain abnormalities and optic nerve hypoplasia. Although the condition is present from birth, it may not be diagnosed immediately. Both males and females are affected.
What causes septo-optic dysplasia?
The exact cause in the majority of cases is unknown. It may be possible that there is a genetic link and the condition can result from a mutation. However, it is very uncommon for the condition to run in families and this suggests that there is no inheritance pattern. Potential risk factors include environmental factors, having a very young mother and complications during pregnancy. However, further research is required to discover more about potential causes.
Who is affected?
Septo-optic dysplasia affects boys and girls equally. It is estimated to affect around 1 in every 10,000 births (this relates to live births).
What are the symptoms?
There are three main symptoms of septo-optic dysplasia and babies are diagnosed with the condition when they have at least two of these key signs. Most commonly, babies have two of the symptoms. Around 33 percent of children have all three characteristics. The three key features include:
Optic nerve hypoplasia: this occurs when the optic nerve doesn’t develop fully during pregnancy, is not as large as expected and does not contain the right number of fibres. This can result in severe vision problems.
Midline brain abnormalities: development may be delayed by the absence or underdevelopment of parts of the midline region, including the corpus callosum and the septum pellucidum. It is common for children to learn to walk and talk later in life and they may also have impaired coordination.
Abnormalities with the pituitary gland: the pituitary gland is responsible for a range of important functions within the body, including the production of hormones. If a child has abnormalities related to the pituitary gland, the secretion of hormones may be abnormal and this can cause various symptoms. Low levels of growth hormone can inhibit physical growth and decrease blood sugar levels. Other potential symptoms of pituitary gland abnormalities include high levels of salt and diabetes insipidus (this is characterised by an insatiable thirst and excessive urinating). Levels of cortisol (the body’s stress hormone) and thyroid hormone may also be affected and this can delay puberty.
Symptoms vary in severity and affect children in different ways. Most commonly, children experience poor vision and delayed development. Gaining weight easily, behavioural problems, disturbed sleep patterns and behaviour associated with autism may also be present.
Diagnosing septo-optic dysplasia
In some cases, this disorder can be diagnosed during routine antenatal scanning. However, most cases are not diagnosed until early childhood. Symptoms such as small genitalia in males, low blood sugar, slow growth and increased susceptibility to infections may all be suggestive of septo-optic dysplasia.
If doctors suspect a diagnosis of septo-optic dysplasia, tests will be ordered to confirm or rule out this condition. Tests including MRI (magnetic resonance imaging) scans, blood tests and vision assessments are conducted.
Treatment for septo-optic dysplasia
Children with septo-optic dysplasia are cared for by a multi-disciplinary team made up of different health professionals, including endocrinologists who specialise in hormones, neurologists who specialise in working with the brain and ophthalmologists who work with vision and the eyes. Physiotherapists and speech and language therapists may also be involved.
The main focus of treatment is to identify the hormone deficiency and use artificial replacements.
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