Chiari malformation type 2 typically occurs sporadically (in individuals with no history of the condition in the family). However, the exact cause of Chiari malformation type 2 is not known. Genes may play a role in predisposing an individual to the condition, but environmental factors (such as lack of proper vitamins or nutrients in the maternal diet during pregnancy) may also contribute to the condition. Because the cause is unclear, it is not currently possible to estimate what the recurrence risk for family members may be.
There have been reports in the medical literature of families in which more than one family member was affected with a Chiari malformation. However, a search of the available medical literature yields limited information specific to familial cases of Chiari malformation type 2. One article written by Lindenberg and Walker in 1971 describes the Arnold-Chiari malformation in 2 sisters; both also had hydrocephalus and meningomyelocele.
Last updated: 8/9/2011
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