Further Outpatient Care
Monitor the need for and response to platelet transfusions by measuring platelet counts.
Further Inpatient Care
Monitor response to platelet transfusions through observation of hemostasis and rise in platelet counts in patients with thrombocytopenia-absent radius (TAR) syndrome.
Deterrence/Prevention
Although the patient is thrombocytopenic, injury-prevention strategies are indicated.
Patients should avoid contact sports and use appropriate protective gear (eg, helmets, padding) when participating in sports or leisure activities.
Complications
Complications arise from hemorrhage and hemorrhagic insults, especially intracranial hemorrhage.
Prognosis
The clinical course is one of episodic, severe thrombocytopenia superimposed on a background of persistent thrombocytopenia. The frequency of thrombocytopenic episodes decreases with age. By school age, near-normal platelet counts are expected. If a patient survives the initial 2 years of life, life expectancy is normal.
The risk of morbidity may be increased. Case reports describe acute leukemia in both pediatric and adult patients with TAR syndrome. This development is not entirely unexpected because other syndromes of bone marrow failure, such as Fanconi anemia and Shwachman-Diamond syndrome, are associated with an increased risk of malignancies. Given the rare incidence of this syndrome, however, identifying a chance association or a causal relationship is difficult.
Jameson-Lee et al reported on an adult male patient with TAR syndrome in whom myelodysplastic syndrome progressed to acute myeloid leukemia (AML). The patient also had a CALR driver mutation, which is uncharacteristic of individuals with TAR syndrome, and no RBM8A mutation, despite the association of this mutation with the syndrome. A review of the literature turned up three other TAR syndrome patients with AML, only one of whom was an adult, and one patient in whom acute lymphoblastic leukemia developed. [27]
Patient Education
Patients and families must be educated about the risk of hemorrhagic injury during episodes of thrombocytopenia, about signs and symptoms indicative of thrombocytopenia (eg, bruising, petechiae, mucosal bleeding), and about the need to promptly seek medical attention during these episodes.
For excellent patient education resources, see eMedicineHealth's patient education article Bone Marrow Biopsy.
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Infant with thrombocytopenia-absent radius syndrome. The arms and forearms are shortened, with radial deviation of both hands because of the absence of bilateral radii. The legs are normal. See also Media files 2 and 3.
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Same infant as in Media files 1 and 3. Close-up photograph of arm and forearm (volar aspect). Note the petechiae.
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Same infant as in Media files 1 and 2. Close-up photograph of arm and forearm (dorsal aspect).
