Marinesco-Sjögren syndrome

Also known as: Cataract-oligophrenia; Hereditary Oligophrenic Cerebellolental Degeneration; Marinesco-Garland syndrome; Marinesco-Sjögren-Garland syndrome; Torsten Sjögren

Background

Marinesco-Sjögren syndrome (MSS) is a rare genetic condition that affects many body systems. Children with the condition may have visual problems including cloudiness of the lens (cataracts), muscle weakness, difficulty coordinating movements, developmental delay, and sometimes learning disability.

More than 200 cases of MSS have been reported worldwide, but most cases are no longer reported in the medical literature.

Credits

Last updated February 2015 by Dr WR Wilcox, Department of Human Genetics, Emory University, USA.

What are the symptoms?

The major features of the condition include:

  • developmental delay – delay in meeting motor milestones (eg sitting without support and crawling)
  • muscle weakness
  • early onset cataracts 
  • congenital cerebellar ataxia – a movement condition due to underdevelopment and/or malfunctioning of the part of the brain controlling movement (cerebellum) causing unsteadiness and lack of coordination
  • dysarthria- problems with speech due to difficulties controlling the tongue and mouth
  • short stature (height)
  • hypergonadotrophic hypogonadism (underactive sexual organs) causing a lack of development at puberty
  • learning disability – in some but not all children.

The extent to which people are affected by the condition varies from person to person.

What are the causes?

Changes (mutations) in the SIL1 gene cause MSS. The SIL1 gene provides instructions for producing a protein located in a cell structure called the endoplasmic reticulum. Among its many functions, the endoplasmic reticulum folds and modifies newly formed proteins so they have the correct shape. The SIL1 protein plays a role in the process of protein folding. Incorrectly folded proteins could accumulate in cells and likely damages and destroys cells in many different parts of the body leading to the symptoms of MSS.

Around a third of people with MSS syndrome do not have identified mutations in the SIL1 gene. In these cases, the cause of the condition is unknown.

How is it diagnosed?

MSS is obvious at birth because babies are hypotonic (have muscle weakness). Although the cataracts are not usually present at birth, they can develop quite rapidly in childhood. The diagnosis is usually based on the symptoms observed but eye examinations to confirm cataracts and a magnetic resonance imaging (MRI) scan of the brain can be helpful. SIL1 gene testing can help make a diagnosis, if there is a mutation present. Many other disorders can resemble MSS, so it is essential to be evaluated by a geneticist familiar with MSS and similar conditions.

How is it treated?

Treatment of MSS involves alleviating the symptoms a child experiences as much as possible. This can involve, for example, removal of the cataracts through surgery, physical therapy to help movement problems, speech therapy, and adapted educational programs. Hormone replacement therapy is also available if there is hypogonadism – this will help to replace missing hormones and bring on puberty.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
MSS is inherited in an autosomal recessive manner.

Prenatal diagnosis 
This is available if the mutation in an affected family has been identified.

Is there support?

Marinesco-Sjogren Syndrome Online Support Network

Email: mss@marinesco-sjogren.org
Website: marinesco-sjogren.org

This small network provides information and support to adults, children and families affected by Marinesco-Sjogren Syndrome. It puts families in touch with one another. The website contains information that is endorsed by medical professionals. 

Group details last updated February 2016.

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