Haptoglobin is one of the most abundant proteins in blood, and plays a role in protecting the body from harmful effects of another blood protein, haemoglobin. Haptoglobin may play an important role in altering the severity of outcomes after brain haemorrhage. We will use the ALSPAC cohort to measure the effects of genetic variants on the levels of haptoglobin. These genetic variants will then be used in a separate study to determine whether haptoglobin levels affect the severity or consequences of brain haemorrhage.