[Familial Bloom's syndrome associated with neuroblastoma]. / Síndrome de Bloom familiar associada a neuroblastoma.

Bloom's syndrome (BS) is an autosomal recessive disease characterized by short stature, sensitivity to sunlight, and telangiectasic malar erythema. It is associated to chromosomal breakage, to primary combined immunodeficiency, and to a high incidence of neoplasias. The authors report the case of two siblings with BS and associated immunodeficiency. Both patients were male and 5 (A) and 4 (B) years old at the time of diagnosis. Chronic diarrhea, recurrent otitis media, purulent rhinitis, conjunctivitis and pyodermatitis were reported by patient A. Patient B was admitted with diagnosis of bilateral neuroblastoma and had the tumor resected. Later on, he presented with oral moniliasis, herpetic stomatitis, and skin abscesses. This patient did not have recurrent infections. Immunological evaluation showed normal serum levels of CH50, C3, and C4 for both patients. Serum IgG, IgA, IgM, and salivary IgA levels were: 455 mg/dl, 15mg/dl, 20mg/dl, 0.6mg/dl for A, and 400mg/dl, 15mg/dl, 20mg/dl, and 0.2mg/dl for B, respectively. Serum antipolio antibodies (1, 2, and 3) were normal, and low levels of isohemagglutinins were observed in both patients. T cells subset determination showed: patient A--OKT3 = 66%, OKT4 = 33%, OKT8 = 32%, and 4/8 ratio = 1.0; patient B--OKT3 = 70%, OKT4 = 32%, OKT8 = 34%, and 4/8 ratio = 1.0. In vitro cellular immune response to PHA was depressed only in patient B. Patients karyotype showed chromosomal breaks with sister chromatid exchanges. Neither patient had abnormal alphafetoprotein and carcinoembryonic antigen serum levels. The rarity of such associations justifies the presentation of the cases.