There’s multiple variants of heterotaxy syndromes (left and right variants) as well as many on a wide spectrum. We see a couple a cases a year pass through the radiology department.

The working understanding is that these are ultimately ciliary dysfunctions in utero which cause aberrant gradients for body patterning.

This condition is called situs inversus. There’s another similar one called dextrocardia where only the heart is on the wrong side (literal meaning is “right sided heart”).

My cousin has it, my mom always blamed it on her parents doing drugs.