Heads of state's families killing each other in combat

Miscellaneous and Personal Stuff I Must Share
1

So I recently fell down a “wikihole” about the 1976 Entebbe Raid, as you do. I learned that current Israeli PM Benjamin Netenyahu’s brother Yonatan led, and was killed in the raid, when Ugandan soldiers in the airport control tower returned fire on Israeli troops

However not only that, according Ugandan accounts the soldier who returned fire, and was then killed himself in the resulting exchange of fire, was Idi Amin’s cousin.

If this is true is this the only time this has happened in modern times? A cousin of one head of state killing another (future) head of state’s brother?

I imagine it was fairly frequent when heads of state and their relatives were expected to don armor together, but can’t imagine it happens that often nowadays.

2

I don’t know the answer to your question, but one minor correction: Netanyahu is a head of government, not head of state.