J. Paediatr. Child Health (1994)30,363-365 Anticardiolipin and acquired protein S deficiency in early childhood R. T. L. COUPER’ and F. C. MAXWELL2 Universityof Adelaide Department of Paediatrics and 2Departmentof General Paediatrics,Adelaide Children’s Hospital, King William Road, North Adelaide, South Australia, Australia Abstract A 27 month old child presented with left hemiplegia and was found to have deep cerebral venous thrombosis. The deep cerebral venous thrombosis resolved on warfarin. Elevated and fluctuating anticardiolipin antibodiesas well as protein S deficiency were detected. Key words: anticardiolipin; deep cerebral venous thrombosis; protein S. Recently, an association between antiphospholipid antibodies (lupus anticoagulant and anticardiolipin) and low circulating plasma free protein S levels was reported in 1 1 women with recurrent fetal wastage.’ Seven women had low plasma free protein S and six had prior clinical thrombosis. The mechanism of protein S depletion is unexplained. The author’s report coexistence of low free protein S, transient anticardiolpin antibodies and deep cerebral venous thrombosis in a 27 month old female. CASE REPORT The child, an identical twin, presented during a mild febrile illness with left (L) hemiplegia that partially resolved over 3 days. Her twin also had a mild febrile illness. No signs of dehydration, trauma, neurocutaneous stigmata, bruits, arteriovenous malformation, systemic lupus erythematosus (SLE) or homocystinuria were detected. Cranial computerized tomography (CT) scan demonstratedextensive hypolucency in the right thalamic body (Fig. 1). Four days after presentation dense right (R) hemiplegia and aphasia developed. Repeat CT scan demonstrated partial resolution of the R thalamic lesion and extensive hypolucency of the L thalamus. The region of the internal cerebral veins, great vein of Galen and straight sinus were hyperdense. A thrombus was seen in the straight sinus. T2 and midline fast imaging and steady state precision (Siemens) magnetic resonance imaging scans confirmed straight sinus thrombosis (Fig. 2). Prothrombintime, activated partial thromboplastin time (APTT) and thrombin clotting time were normal as were the serum fibrinogen and fibrin degradation products. The protein C level was 86% (normal 70-140%). the plasma free protein S level measured by Laurel rocket immunophoresisafter polyethylene glycol precipitation was 28% (normal 65-150%). Her twin had Correspondence: Dr R. Couper. University of Adelaide Department of Paediatrics. Adelaide Children’s Hospital, King William Road, North Adelaide, SA 5006, Australia. R. T. L. Couper, MB, ChB, FRACP, Senior Lecturer. F. C. Maxwell, MB, ChB, Chief Resident Accepted for publication 3 February 1994. protein C and free protein S levels of 86 and 81%, respectively. Antithrombin 111 levels were not measured. Antinuclear, native DNA and extractable nuclear antigen antibodies were not detectable. Serum anticardiolipins measured by a validated inhouse enzyme-linked immunosorbent assay (ELISA) at the Institute of Medical and Veterinary Science, University of Adelaide were elevated; immunoglobulin (lg) G 32 arbitrary units (normal