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Thrombocytopenia and absent radius (TAR) syndrome in pregnancy
  1. Elisa Pereira,
  2. Ana Regalo,
  3. Lara Caseiro,
  4. Joaquim Carvalho
  1. Hospital Espírito Santo, Évora, Portugal
  1. Correspondence to Dr Elisa Pereira, elisa_pereira{at}

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A healthy 36-year-old Caucasian woman, P2002, a non-smoker who did not consume alcohol, with no history of exposure to teratogenic agents, presented, at a gestational age of 15 weeks, for prenatal care at our hospital. Ultrasound findings showed a live fetus with bilateral absence of the radius, with club hands, unilateral renal agenesis, a small stomach and cardiac anomalies. In this situation, with a high suspicion of fetal polymalformative syndrome, an amniocentesis was performed, with consent of the patient, at 16 weeks. The cytogenetic analysis demonstrated a normal male karyotype and the study for Fanconi anaemia was negative. It was not possible to carry out thrombocytopenia and absent radius (TAR) syndrome studies. A fetal echocardiogram was performed at 19 weeks and the diagnosis of type I truncus arteriosus was made, with non-restrictive ventricular septal defect. The patient and her husband, after counselling, opted for a medical interruption of pregnancy. This was performed at 24 weeks of gestation. A male abortus weighing 589 g was delivered. Postnatal findings confirmed a syndrome with malformations of the upper limbs, as seen on the subsequent radiograph (figure 1) and macroscopic findings (figures 2 and 3). Umbilical cord puncture was made for the evaluation of fetal platelet counts. Thrombocytopenia (23 000/μL) was found in this case. The autopsy showed bilateral absence of the radius, with normal thumbs, oesophageal atresia, tracheo-oesophageal fistula, unilateral renal agenesis, one single umbilical artery and a congenital cardiovascular anomaly (truncus arteriosus), without congenital vertebral anomalies. Thrombocytopenia and autopsy findings confirmed the diagnosis of TAR syndrome.

Learning points

  • Radial aplasia is associated with chromosomal, teratogenic and genetic causes.1 Thrombocytopenia is mandatory to differentiate thrombocytopenia and absent radius (TAR) syndrome from other malformations of the upper limbs.

  • TAR syndrome is a rare disorder characterised by the absence of the radius; it is usually bilateral and presents a reduced platelet count.2

Figure 1

Radiograph of the fetus showing bilateral absence of the radius.

Figure 2

Male fetus after medical interruption of pregnancy.

Figure 3

Macroscopic findings: club hands.


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  • Competing interests None declared.

  • Patient consent Not obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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