Kindred
An extended family or clan, a group of related individuals.
The term 'kindred' is used in population studies of diseases or genetic traits.
For example, a syndrome of progressive retinal disease, endocrine (hormonal) abnormalities and degenerative liver disease was observed in eight patients, seven of whom belonged to one very large kindred.
'Kindred' is composed of two parts: 'kin' + '-dred.' Kin is Middle English and referred to birth, race, kind.
The '-dred' part is derived from 'raeden' (condition) which in turn came from 'raedan' (to advise).