GTR Home > Conditions/Phenotypes > Radial aplasia-thrombocytopenia syndrome

Disease characteristics

Excerpted from the GeneReview: Thrombocytopenia Absent Radius Syndrome
Thrombocytopenia absent radius (TAR) syndrome is characterized by bilateral absence of the radii with the presence of both thumbs and thrombocytopenia (<50 platelets/nL) that is generally transient. Thrombocytopenia may be congenital or may develop within the first few weeks to months of life; in general, thrombocytopenic episodes decrease with age. Cow’s milk allergy is common and can be associated with exacerbation of thrombocytopenia. Other anomalies of the skeleton (upper and lower limbs, ribs, and vertebrae), heart, and genitourinary system (renal anomalies and agenesis of uterus, cervix, and upper part of the vagina) can occur.

Associated genes

  • Also known as: HSPC114, BOV-1A, BOV-1B, BOV-1C, C1DELq21.1, DEL1q21.1, MDS014, RBM8, RBM8B, TAR, Y14, ZNRP, ZRNP1, RBM8A
    Summary: RNA binding motif protein 8A

Clinical features

  • Thrombocytopenia
  • Anemia
  • Coxa valga
  • High forehead
  • Short stature
  • Aplasia of the uterus
  • Hooked clavicles
  • Broad thumb
  • Tibial torsion
  • Hypogammaglobulinemia
  • Adducted thumb
  • Fibular aplasia
  • Talipes equinovarus
  • Bilateral radial aplasia
  • Nevus flammeus of the forehead
  • Seborrheic dermatitis
  • Coarctation of aorta
  • Vertebral segmentation defect
  • Finger syndactyly
  • Anteverted nares
  • Broad forehead
  • Low-set, posteriorly rotated ears
  • Malar flattening
  • Ventricular septal defect
  • Pancreatic cysts
  • Carpal synostosis
  • Cavum septum pellucidum
  • Micrognathia
  • Carpal bone hypoplasia
  • Seizure
  • Shoulder muscle hypoplasia
  • Strabismus
  • Eosinophilia
  • Cleft palate
  • Edema of the dorsum of hands
  • Horseshoe kidney
  • Brachycephaly
  • Sensorineural hearing impairment
  • Ptosis
  • Cervical ribs
  • Global developmental delay
  • Motor delay
  • Cerebellar hypoplasia
  • Hepatosplenomegaly
  • Defect in the atrial septum
  • Tetralogy of Fallot
  • Abnormality of the cardiac septa
  • Abnormality of coagulation
  • Delayed CNS myelination
  • Abnormality of the intestine
  • Meckel diverticulum
  • Spina bifida
  • Scoliosis
  • Hip dislocation
  • Fused cervical vertebrae
  • Genu varum
  • Patellar dislocation
  • Abnormality of the shoulder
  • Clinodactyly of the 5th finger
  • Axial malrotation of the kidney
  • Patellar aplasia
  • Aplasia/Hypoplasia of the ulna
  • Aplasia/Hypoplasia of the humerus
  • Phocomelia
  • Cow milk allergy
  • Abnormal localization of kidney
  • Edema of the dorsum of feet
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