Cerebro-costo-mandibular syndrome

The majority of cases of cerebro-costo-mandibular syndrome (CCMS) appear to occur sporadically (randomly), in people with no history of the condition in their family. However, familial cases have been reported (almost half of all cases), with both autosomal recessive and autosomal dominant inheritance described. To date, the underlying cause of CCMS has not been identified.

In a person with an autosomal recessive condition, both copies of the responsible gene in each cell must have a change (mutation). In these cases, the affected person usually inherits one mutated copy of the gene from each parent, both of whom are likely unaffected.

In a person with an autosomal dominant condition, having only one mutated copy of the responsible gene in each cell is enough to cause signs or symptoms of the condition. An autosomal dominant condition may be inherited from an affected parent, or the mutation may occur for the first time in the affected person. When someone with an autosomal dominant condition has children, each child has a 50% (1 in 2) risk to inherit the mutated gene.

Affected people from families suggesting autosomal recessive or autosomal dominant inheritance have overlapping features. In both groups, the severity varies, both among affected members of the same family and between families. The different patterns of inheritance seen support the likelihood that there is more than one genetic cause of CCMS.

The likelihood that cerebro-costo-mandibular syndrome (CCMS) would be passed from an affected parent to a child depends on the underlying cause of the condition (which is currently unknown) and the inheritance pattern associated with that cause.

For example, if a parent has CCMS and has one mutated copy of the responsible gene, that parent has an autosomal dominant form of CCMS. In this case, each child of the affected parent has a 50% (1 in 2) risk to inherit the mutated gene and be affected.

If a parent has an autosomal recessive form of CCMS (which means having a mutation in both copies of the responsible gene) and has children with an unaffected partner, every child would likely be an unaffected carrier of CCMS. Carriers of autosomal recessive conditions usually do not have any signs or symptoms.

It is important to note that because the underlying cause of CCMS has not been identified, it may be difficult to know the inheritance pattern present in a family. This is especially the case when only one person in a family is affected. It may not be possible to tell whether the affected person has one mutation that occurred for the first time (in which it would be autosomal dominant), or has two mutations that were inherited from carrier parents (in which case it would be autosomal recessive).

People with a family history of CCMS who are interested in learning more about the inheritance and risks to themselves or family members should speak with a genetics professional.

Because CCMS is very rare and familial cases have been reported, it would be extremely unlikely that a parent and child would both be affected by chance.