Venesection in haemoglobin Yakima, a high oxygen affinity haemoglobin.

High oxygen affinity haemoglobins result in polycythaemia and cardiovascular adaptation to maintain tissue oxygenation. The polycythaemia can cause symptoms of hyperviscosity and vaso-occlusive disease. We report a kindred with a high affinity haemoglobin (Haemoglobin Yakima) one of whose members gave birth to two infants with intra-uterine growth retardation and who suffered with symptoms of hyperviscosity which settled on reduction of the PCV by venesection.