И лишь небольшое колличество ученых

И лишь небольшое колличество ученых считают что на развитии синдрома Каннера влияют внешние факторы ( неблагополучные семьи, воспитание в детском доме) 
Видимо, в развитии аутизма у детей принимают участие совокупность причин. 

Результаты (английский) 1:

And only a small number of scholars believe that the development of Kanner's syndrome is affected by external factors (dysfunctional families, raised in an orphanage)
apparently in the development of autism in children are a set of causes. 

Результаты (английский) 2:

And only a small Number of scientists believe that the development of Kanner's syndrome is influenced by external factors (dysfunctional families, at an orphanage) 
Apparently, in the development of autism in children are involved set of reasons. 

Результаты (английский) 3:

And only a few not logged scientists believed that the development acquired Каннера affect external factors ( disadvantaged families, education in the children's home)
apparently,In the autism spectrum disorders in children are involved the combination causes.