11 POLISH PATIENTS WITH MICROCEPHALY, IMMUNODEFICIENCY, AND CHROMOSOMAL INSTABILITY - THE NIJMEGEN BREAKAGE SYNDROME

We report on 11 patients from 8 independent families (3 pairs of sibs) with a complex clinical pattern including microcephaly, peculiar ''bi rd-like'' face, growth retardation, and, in some cases, mild-to-modera te mental deficiency. Most of the patients have recurring respiratory tract infections. One girl has developed B-cell lymphoma. A detailed a nthropometric study of 15 physical parameters, including 3 cephalic tr aits, was performed. It was possible to study the chromosomes of PHA-s timulated lymphocytes in all of the patients. We found structural aber rations with multiple rearrangements, preferentially involving chromos omes 7 and 14 in a proportion of metaphases in all individuals. Profou nd humoral and cellular immune defects were observed. Serum AFP levels were within normal range. Radioresistant DNA synthesis was strongly i ncreased in all 8 patients who were hitherto studied in this respect. Our patients fulfill the criteria of the Nijmegen breakage syndrome, w hich belongs to the growing category of ataxia telangiectasia-related genetic disorders. In light of the increased predisposition to maligna ncy in this syndrome, an accurate diagnosis is important for the patie nt. (C) 1995 Wiley-Liss, Inc.