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An extended family with three individuals affected by two different forms of double heterozygosity for beta-thalassemia and Hb New York is reported. Double heterozygosity of Hb New York [beta 113 GTG-->GAG; VAL-->GLU] and beta degrees codon 17 was detected in a fetus following prenatal screening for thalassemia. The father and a paternal aunt were also found to be heterozygous for Hb New York and beta degrees IVSII-654. Both adults had clinical and hematological features consistent with beta-thalassemia trait. The affected child was followed up after birth and manifested the typical course of a thalassemia trait, with no signs of organomegaly or overt hemolysis. Observations strongly suggest that double heterozygosity of Hb New York and beta degrees thalassemia has mild, if any, clinical symptoms, and is not an indication of therapeutic abortion when detected antenatally.

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OBJECTIVE: To determine the incidence of venous thromboembolic disease in children of Chinese origin, and associated predisposing factors. DESIGN. Retrospective case series. SETTING: A general, public hospital serving a population of approximately 181,000 children in Hong Kong. PATIENTS AND METHODS: Hong Kong Chinese children under the age of 15 years who were diagnosed with a symptomatic venous thromboembolic event between 1995 and 2000 were included. Data on clinical features, predisposing factors, treatment, and outcome were obtained from review of hospital medical records. RESULTS: Eight children (five girls and three boys) of mean age 11.5 years (range, 0-14.7 years) were included in the study. They presented with deep vein thrombosis (n=4, with pulmonary embolism in one), superior vena cava thrombosis (n=1), and cerebral venous sinus thrombosis (n=3). Predisposing factors included hereditary protein C deficiency (n=3), protein S deficiency (n=2), anticardiolipin antibodies (n=1), malignancy (n=3), recent neurosurgery (n=2), infection (n=1), with multiple predisposing factors seen in three patients. Anticoagulant therapy was prescribed in five patients, and long-term warfarin therapy was required in two cases. Venous thromboembolic disease resolved in all children, but one patient had a recurrence after cessation of warfarin therapy, and one patient had post-thrombotic syndrome. CONCLUSION: The rate of venous thromboembolic disease in Hong Kong Chinese children was comparable to that seen in Caucasian children, with an annual incidence of 0.74 per 100,000 children. Predisposing factors, including hereditary prothrombotic conditions, were common.

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Two cases of anti-Dib, a rarely encountered antibody, were identified in serum samples referred by hospital blood banks during the past 13 months. Case 1 is a 41-year-old female who required blood for elective surgery. Case 2 is a premature infant suffering from mild neonatal jaundice on day 2 after birth. The anti-Dib in both cases exhibited marked dosage effect. The titer/score against Di(a+b+) and Di(a-b+) red blood cells (RBCs) in case 1 was 8/10 and 32/32, respectively, and in case 2, 4/18 and 32/46. The monocyte monolayer assay (MMA) also gave a similar pattern of results, being l5 percent and 100 percent reactive when tested with Di(a+b+) and Di(a-b+) RBCs in case 1, and 0.4 percent (within normal range) and l4.4 percent in case 2. The patient in case 1 underwent her operation without blood transfusion. The infant in case 2 was treated by phototherapy and subsequently recovered without the need for exchange transfusion.

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The fifth child of a Hong Kong Chinese mother developed moderate jaundice, attributable to antibodies (anti-Mi) against antigenic determinants in GP.Mur (Miltenberger, class III) red cells. Both the father and the eldest sister were of the phenotype GP.Mur. Testing of maternal serum against a red cell panel including cells known to carry the antigenic determinants of some Miltenberger phenotypes revealed the presence of anti-Mur. This report documents the first case of haemolytic disease of the newborn (HDN) due to anti-Mur in Hong Kong.

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Three cases of juvenile chronic myeloid leukemia (JCML) are reported. The patients were aged 3-4.5 years and presented with generalized lymphadenopathy, hepatosplenomegaly, anemia, thrombocytopenia, elevated white blood cell count with monocytosis, and high fetal hemoglobin level. Philadelphia chromosome was absent in two cases studied. The bone marrow showed myeloid hyperplasia with increased monocytoid cells and blasts. Biopsy or postmortem material available in two cases revealed malignant infiltration of lymph nodes, liver, spleen, lungs, intestines, and skin. The neoplastic cells ranged from cells with irregular nuclei possessing nuclear grooves to large blastic cells with round to lobulated nuclei and prominent nucleoli. They showed weak staining for acid phosphatase and nonspecific esterase and exhibited the immunophenotype EBM11+KiM1+KiM6+KiM8+CD4+HLADR+ S-100 protein+. The neoplastic cells of JCML therefore share features of dendritic cells and mononuclear phagocytes. The authors' findings show that JCML is a unique histiocytic malignancy in which S-100 protein is a useful marker.

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A patient with immunohistochemically confirmed nasal T-cell lymphoma is reported. He developed systemic histiocytosis with marked hemophagocytosis, simulating malignant histiocytosis. The differential diagnosis from the latter is discussed.

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A 38 yr-old man has chronic non-spherocytic hemolytic anemia which was attributed to glucose-6-phosphate dehydrogenase (G-6PD) deficiency for the past 20 yr. A diagnosis of congenital dyserythropoietic anemia Type II (CDA) was made because of the bone marrow findings and electron microscopic appearance of the peripheral erythrocytes. Congenital dyserythropoietic anemia, though well recognized in Caucasians, has not hitherto been described in Chinese. Erythrocyte G-6PD deficiency has been found to have an incidence of 5.5% in Southern Chinese. The coexistence of CDA Type II and G-6PD deficiency in this patient may be a chance finding or there may be an interaction between the 2 abnormalities in the clinical manifestations of CDA Type II and G-6PD deficiency.

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