Deletion of the factor IX gene as a result of translocation t(X;1) in a girl affected by haemophilia B

A balanced de novo translocation t(X;1) is described in a girl with severe haemophilia B. The translocated X was shown cytologically to be preferentially active, and methylation analysis of the DXS255 locus confirmed the skewed X-inactivation with the paternal allele being the active one. Cytogenetic and molecular analysis showed that this chromosomal rearrangement led to the deletion of at least part of the factor IX gene. Therefore, the girl was heterozygous for factor IX deficiency and expression of her clinical phenotype was the result of the inactivation of the normal maternal X chromosome. The localization of one of the X chromosome translocation breakpoints in YAC clone 957F9, that was demonstrated to map distally to the factor IX gene, revealed the complexity of this chromosomal rearrangement.

Simultaneous occurrence of advanced neuroblastoma and acute myeloid leukemia

The authors report the case of a 4-year-old boy with a diagnosis of stage IV neuroblastoma (NB), who had been treated with 6 cycles of cyclophosphamide, doxorubicin, cisplatin, and etoposide for 12 months. The patient reached partial remission and presented a diagnosis of acute myelomonocytic leukemia (M4 AML), confirmed by immunophenotyping. After 2 months of therapy for leukemia, the child died with both malignancies in activity. A necropsy histologically confirmed the simultaneity of the two diseases. The authors review the possibilities of this association. The review leads to the conclusion that AML can occur as a secondary malignancy after the onset of the neuroblastoma, or be suggested by a misdiagnosis. The simultaneous occurrence of both as described here is not, however, found in the literature, to the best of the authors' knowledge.

Disseminated Langerhans' cell histiocytosis and massive protein-losing enteropathy

Symptomatic involvement of the gastrointestinal (GI) tract as a prominent symptom in Langerhans' cell histiocytosis (LCH) is uncommon, occurring in less than 1 to 5% of all cases, even when the disease is in its disseminated form. Up to now, there have been reports of 18 cases of LCH with GI manifestations, including our 2 cases, with diarrhea (77.7%), protein-losing enteropathy (33.3%) and bloody stool being the most frequent findings. The authors present two patients with severe diarrhea and refractory hypoalbuminemia, and with the protein-losing enteropathy documented by Cr51-labeled albumin studies. A review of the literature indicated that the presence of GI symptoms is often associated with systemic disease as well as with poor prognosis, mainly under 2 years of age. Radioisotopes are useful for documenting protein loss in several diseases with high specificity and sensitivity, and their utilization in the cases reviewed here permitted diagnoses in 6 children, as well as improved therapeutic management.

Neuroblastoma in a boy with MCA/MR syndrome, deletion 11q, and duplication 12q

Deletion 11q23-->qter and duplication 12q23-->qter are described in a boy with neuroblastoma, multiple congenital anomalies, and mental retardation. The patient has clinical manifestations of 11q deletion and 12q duplication syndromes. The possible involvement of the segment 11q23-->24 in the cause of the neuroblastoma is discussed.

Toxocariasis simulating hepatic recurrence in a patient with Wilms' tumor

We report the case of a 3-year-old girl with stage I Wilms' tumor of favorable histology. During the course of chemotherapy 5 months post-diagnosis, an abdominal ultrasonogram revealed hypoechoic areas consistent with hepatic tumor recurrence. A liver biopsy performed to rule out recurrence of the malignancy was suggestive of toxocariasis and the diagnosis was confirmed by serologic testing. Although the patient had few classic signs of visceral larva migrans, her eosinophilia and family social history should have suggested this possibility. This case demonstrates that hepatic toxocariasis should be considered in evaluating hepatic hypoechoic lesions in a child, even when features typical of the disease are absent.

Administration of live attenuated varicella vaccine to children with cancer before starting chemotherapy

From July 1985 to February 1987, of 46 consecutive children with cancer (26 male, 20 female; median age, 4 years) with no prior history of chickenpox, the initial 30 patients were randomized either to receive or not to receive live attenuated varicella vaccine (LAVV) before chemotherapy was started and the remaining 16 patients were all immunized without randomization. Before immunization, Varicella zoster (VZ) antibodies were detected by immunofluorescence and ELISA in 11 (34%) of 32 vaccinated children and two (14%) of 14 controls, indicating previous infection. A booster effect was evident in 70% of them and no side effects were noted. Ten (28%) of 32 vaccinees were excluded from the analysis because of early death due to cancer (1-4 weeks). Seroconversion was demonstrated in ten (77%) of 13 vaccinees, with high antibody titres. Only three of them lost their antibodies 2 years after immunization, as disclosed by serological follow-up. Eight out of 13 vaccinees had household contacts with VZ and none became infected. Zoster immunoglobulin (ZIG) was never given. Among controls, seven out of 14 were exposed to VZ and four (57%) became infected. Mild side effects were observed in four (12.5%) out of 32 vaccinees (three with papulovesicular rash, 6-30 lesions, and one with a 3-day intermittent fever). Local reactions, zoster and spreading of vaccinal virus did not occur. LAVV proved to be safe and effective when administered before starting chemotherapy to children with cancer and no history of varicella.