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Gorlin Syndrome Group

Supporting patients, their families and carers
 
Registered Charity No: 1096361
Supporting patients, their families, friends and carers affected by Gorlin Syndrome
Home      About the Syndrome      Skeletal

The Skeletal system
The Gorlin Syndrome gene also has an effect on the development of the skeletal system. This does not progress throughout life, and usually causes no ill effects at all. The signs in the bones found in X-ray may be helpful in making the diagnosis.
 
 
Principally affected are the height, the shape of the ribs, the shape of the bones in the vertebral column, and the shape of the skull. Epsum factorial non deposit quid

Height

People with Gorlin Syndrome can be much taller than expected for their family.

Shape and size of the skull

The size of the skull is usually larger than average (usually over 60 cm in adults) - some people have difficulty in getting hats. The front of the skull and forehead may be very prominent, the bone being especially protruberant above and over the outer parts of the eyes (this is called 'frontal and parietal bossing').

A large proportion of babies with Gorlin Syndrome require delivery by Caesarian section because of the large head size.

The face

Because of the growth of the skull, about 70% of people with Gorlin Syndrome have eyes which appear wider apart that usual. There is variation between family members, as with all features of the syndrome. Some members of a sibship may have the typical face to the skull, for instance, whilst other do not.

Spine and chest

60% of people with the syndrome have one or more ribs which can be bifid, wide, fused, partially missing or underdeveloped. These changes in the ribs do not cause problems apart from perhaps giving an unusual shape to the chest, including a characteristic downward sloping of the shoulders. The rib abnomalies can give rise to a prominent or depressed breast bone (sternum) in about 30% - 40% of patients.

There can be unusual appearances to one or more bones in the spine in the neck and upper chest in about 60% of people with the syndrome. These again do not usually cause problems, but can be helpful in diagnosis. The appearances can be of a vertebra not having formed correctly, appearing as through there were a cleft in it, or of vertebra have fused together.

Other bones can be involved

Extra digits on the hand and feet can occur. Many patients comment that the big toe can be stiff with a prominent joint at the base of the toe. It this becomes troublesome, with pain, or difficulty in obtaining suitable shoes, then an operation can cure the problem.

In about 35% of people with the syndrome, an X-ray of the hands will show small cysts in the bones of the fingers. The numbers and site can be very variable. Bone cysts can also occur in the long bones of the arms and legs, the pelvis and the skull. These do not usually cause problems.

Ectopic calcification

A feature of the syndrome which has not yet been explained is that various parts of the body are prone to develop excess calcium in them. This too has no effect on the person, but can be useful in confirming the diagnosis of Gorlin Syndrome (but it can also be found in people who do not have the syndrome).
Calcification of a central membrane which separates the two halves of the brain (the falx cerebri) occurs in at least 85%. The calcification can appear very early in life, and is often strikingly apparent from late childhood. It has a characteristic appearance, seeming to be composed of separate sheets of calcification, in comparison with the single sheet of calcification found in 7% of the normal older population.
 
Calcification can also occur in other membranes, in the brain and are seen as white lines on X-rays. This is of no consequence but may well cause excitement if X-rayed.

 

 
 
 
 
Written and produced by Professor P A Farndon, Clinical Geneticist at the National Genetics Education and Development Centre UK, Jim Costello (deceased) & Margaret Costello, unless otherwise stated.