The simian crease is one of the listed signs in Down Syndrome which would imply there's some genetic factor at play. My eldest daughter has a simian crease on one hand and the other hand is 'normal'.
Sovereign definition, a monarch; a king, queen, or other supreme ruler. See more.
Jurisdiction has two important legal meanings. For one, it means having the power or authority to apply or enforce the law. For the other, it means the geographic area or boundaries where that power is good or valid.