Malignant mesothelioma in two pairs of siblings: is there a hereditary predisposing factor?

: Two pairs of siblings with malignant pleural mesothelioma are reported. One sister and brother experienced slight household asbestos exposure during childhood. Two identical-twin brothers were occupationally exposed to asbestos for only 8 years. The occurrence of this rare neoplasm in 2 pairs of siblings indicates that a hereditary predisposing factor may exist.