Origin of mutation in sporadic cases of haemophilia-B
Of the 45 haemophilia-B patients registered at the haemophilia centre in Malmo, Sweden, 24 are the sole members of their families to be affected, and in 13 of these 24 cases, ascendant relatives are available for study. Detection of the gene defect showed the mutation to be de novo in the proband in 3 of these 13 cases, and inherited from a carrier mother in the remaining 10 cases. All 10 carrier