BEN is related to family history, in which several members of one family or several generations may be affected, although no specific genetic marker has been identified. [6],[28] A case-control study showed that individuals whose mother had BEN were 48-times more likely to have the disease than other BEN patients, which suggests that a maternal history is an important risk factor, and the possible existence of a sex-linked trait. [29] A person whose father had BEN was about 8.8-times more likely to develop the disease. This finding motivated us to evaluate whether maternal history of BEN was a stronger predictor of BEN than paternal history.