TAR syndrome

TAR Syndrome (Thrombocytopenia and Absent Radius) is a rare genetic disorder which is characterised by the absence of the radius bone in the forearm, and a dramatically reduced platelet count. Platelets are the clotting agent in blood. A lowered count leads to bruising, and at worst, life-threatening haemorrhage. For most people with TAR, platelet counts improve as they grow out of childhood. more...

Other common links between people with TAR seem to include heart problems, kidney problems, knee joint problems and frequently lactose intolerance.

Treatments range from platelet transfusions through to surgery aimed at 'normalising' the appearance of the arm, which is much shorter and 'clubbed.' There is some debate pro and anti surgery. The infant mortality rate has been curbed by new technology, including platelet transfusions, which can even be performed in utero. The critical period is the first year of life.

Genetic research is underway. It is now known to involve an autosomal recessive gene, hence when a child has the condition any future siblings have a 25% chance of also having it.

The Internet is proving to be a valuable gathering place for people with TAR, who have until now often felt isolated by the rarity of the condition, which is only 0.42 per every 100,000 live births.

Read more at Wikipedia.org