Late discovery of a case with TAR syndrome who presented with an additional potential bleeding risk other than thrombocytopenia

Abstract

The name of this syndrome based on an acronym describing the so called 'most obvious' clinical features: Absent Radii & Thrombocytopenia (TAR). There may however be more to TAR cases than what the name says. Development of molecular genetics has provided us with more information and given us a better understanding of these rare conditions. The deletion of chromosome 1q21.1 associated with TAR syndrome, involves the RBM8A gene which is associated with the production of certain cellular proteins. A newly referred 33 year old woman presented with conspicuous upper limb deformities in the presence of thrombocytopenia (platelets 63) at one of our clinics. The patient was never diagnosed nor given a specific name for her abnormal physical appearance in the past. Plain x-rays of the forearms confirmed absent radii. An ultrasound of the abdomen to exclude splenic sequestration of the platelets surprisingly revealed lesions in keeping with arterio-venous malformations/ haemangioma of the liver. It was uncertain if this finding was related to TAR syndrome, however not unlikely as these cases may present with other arterio-venous malformations, like facial haemangiomas and intracranial vascular malformations. The bleeding risk associated with this finding and particularly in this patient with thrombocytopenia was of great concern. The case was also referred to the hepatology team for further management of the hepatic haemangioma. One can conclude from this case that patients with suspected TAR syndrome may require more detailed imaging as there are many other features, some quite life threatening, which are not included in the short acronym based name.