Hi there!

To predict whether the disease in a pedigree is autosomal or X-linked follow the given steps:

1. Find each of the affected female individual.

2. Check that the affected female individual has an affected father and sons or not.

   (i) If each of the affected female has an affected father and all affected sons, then the trait is X-linked.

   (ii) If even one of the affected female does NOT has an affected father and all affected sons, then the trait is autosomal.

Upon such investigation, work out a cross, to be assured about the answer. 

Thanks