Having a family history of neural tube defects or Down's syndrome does not predispose to a higher risk of the other condition. To identify an association between neural tube defect, hydrocephalus, and Down's syndrome, Amorim and colleagues analysed data on more than 1.5 million children born in South America between 1982 and 2000. They found that the expected and observed numbers of cases of Down's syndrome, hydrocephalus, and neural tube defect were similar regardless of the family history. A link between the conditions, previously described by other researchers, could not be confirmed.
Figure 1.
Credit: LAUREN SHEAR/SPL