Learn Farsi: اینکه شما ژن این جد را دارید، مهم است. - The fact that you have this ancestor's gene is important.

The word inke (the fact that) is used to turn the entire clause shoma zhen-e in jad ra darid (you have this ancestor's gene) into a single noun phrase. This whole chunk then acts as the subject for the main sentence's verb, ast (is).

Why does the direct object marker ra appear after jad instead of right after zhen (gene)?

In Farsi, the marker ra always attaches to the very end of the entire noun phrase. Since the direct object is the whole phrase zhen-e in jad (this ancestor's gene), ra must go at the end, not immediately after the head noun zhen.

Where is the invisible ezafe in this sentence?

There is an ezafe (pronounced "-e") linking zhen (gene) to in jad (this ancestor). You read it as zhen-e in jad, which literally means "gene of this ancestor". As usual, this short vowel isn't written in the standard script.

Why are the verbs darid and ast so close to each other?

They belong to two different clauses. darid (you have) is the verb for the dependent clause about the gene, and because Farsi puts verbs at the end, it wraps up that thought. Then, mohem ast (is important) provides the predicate for the main sentence. The comma helps visually separate the two clauses.