Sequeira served as physician extraordinary to the Portuguese Embassy at the Court of St James's in London, and honorary physician extraordinary to the Portuguese prince regent.[3]
Sequeira married Esther d'Aguilar (1739-1791), the daughter of Baron Diego Pereira d'Aguilar. In Jews and Medicine: An Epic Saga, Frank Heynick describes him as "wealthy and pompous".[3]
His descendants include Jane Sequeira, a British doctor married to the financier Jonathan Ruffer, who collects Spanish old masters and Gainsborough paintings.[1][6]