My g-g-grandmother, the daughter of British immigrants (Staffordshire), died at age 43 in 1893. I have very little personal information about her, but one of her brother's descendants who was in possession of his journal, said that what he wrote of his sister made it sound as if she had some sort of 'mental problem' or 'mental disability'. I didn't get to see what was specifically written, and had no idea about the seemingly genetic pattern of disease in my the family at that time.
Since then, I've come to discover that two of her sons, including my great-grandfather, also died at very young ages and there is documentation on his brother suffering from "St. Vitus Dance" and "chronic chorea", which lead to his death at age 40. My great-grandfather died at age 36 and had suffered from 'paralysis', as was passed down verbally and confirmed by his wife's obituary.
Two of my great-grandfather's children died at age 7, the death certificate of one citing cause of death as 'Disseminated Schlerosis of the brain and spinal cord with paralysis as a complication'. It also said the child had suffered from the condition for about 4 years prior to his death. There is no record of the daughter's death soon after, but what was passed down verbally as the cause was the 'spinning disease' and that seemed to be attributed to both children's deaths and perhaps their father as well. Since Juvenile onset of Huntington's has been linked with it being passed from the father, this supports the theory that both my great-grandfather and his two older children might have had HD. My grandfather (1900-1968), a younger sibling to the two who died at age 7, seems to have been unaffected and died at age 68, but his younger brother who survived childhood, died at age 28 and we have no record of cause. By age 30, my grandfather was the sole survivor of this family (his mother also died when he was 10), and unfortunately he refused to talk about his family of origin later in life, so we only have historical information to work from.