People with twins in their extended families may wonder whether a crib for two is in their future, too. According to conventional wisdom twins not only run in families, but they also-for some strange reasons - skip at least one generation. It is acclaimed that it is widely repeated, but only partly true. Scientists have known for sometimes that there is a gene that can predispose woman to hyper ovulation, or releasing two or more eggs in a single menstrual cycle. When both eggs are fertilised, the resulting siblings are fraternal twins. Because this gene can be passed on, the tendency to have fraternal twins can in fact run in families. Identical twins, on the other hand, result from one fertilised egg randomly splitting in two, creating two siblings with identical DNA. The notion that twins always skip a generation is also a myth.
