Experts estimating that a "twins family" have a genetic problem

There is a village  known now as the "twins town", because there are five pairs of twins. Except for a pigeon pair, the rest four pairs of twins all belong to one big family. However, the "twins family" has suffered a lot. Pediatric experts of Hunan Provincial Children's Hospital said that  exclude those who taking medicine, the twins are mostly hereditary. If all the four pairs of twins have the same physical problems, then they need have genetic inspections.
 
According to Mr. Luo Guoquan, his uncle' s daughter gave birth to twin sisters decades ago, but only one of the twins survived.The same tragedy happened to his aunt, and again to his cousin two years ago.
 
According to Genetic experts, it is not too surprising to have four pairs of twins in one big family because twins can be genetic.
 
But the reason why all the four pairs of twins in the family encounter the some problem is mysterious. The doctor said it may be related to the environment and medicine impact; and premature is also another possible reason, for twins are relatively more likely to be premature.