 Meanwhile, a lab led by Catherine Boileau at the Necker-Enfants Malades Hospital in Paris had been following families with familial hypercholesterolaemia, a genetic condition that, in 90% of cases causes coronary artery disease (FRAMINGHAM study) and in 60% of cases may lead to an early death; they had identified a mutation on chromosome 1 carried by some of these families, but had been unable to identify the relevant gene.The labs got together and by the end of the year published their work, linking mutations in the gene, now identified as PCSK9, to the condition.In their paper, they speculated that the mutations might make the gene overactive.