Sister chromatid exchanges in Bloom's syndrome

Abstract

The importance of chromosome instability in Bloom's syndrome is reviewed, and the recently developed technique for demonstrating sister chromatid exchanges (SCE) is described. In Bloom's syndrome, but not in other heritable syndromes associated with chromosome instability, there is a nine- to ten-fold increase in the frequency of spontaneous SCE. We present a case of Bloom's syndrome in which this test facilitated the diagnosis. In four obligate heterozygotes (the parents of children with Bloom's syndrome), however, an increase in the frequency of spontaneous SCE was not observed.

Clinical and laboratory findings in 8 patients with Bloom's syndrome

“…2,14,15 Chromosomal instability is manifest by an increase in the frequency of chromosome breakage and somatic recombination, which associated with immunologic deficiency is a predisposing factor to develop cancer. 16 The risk of occurrence of neoplasia is a major concern for BS patients. Solid tumors are the most common cancers involving the breast, uterus, larynx, colon, followed by leukemia and Hodgkin lymphoma.…”

“…Solid tumors are the most common cancers involving the breast, uterus, larynx, colon, followed by leukemia and Hodgkin lymphoma. [16][17][18][19] Colon adenomas, predisposing to cancer have been described in one patient. 17 …”

Lupus-Like Histopathology in Bloom Syndrome: Reexamining the Clinical and Histologic Implications of Photosensitivity

“…32 Solitary cytoid bodies, such as those observed in Dicken's patient, that stain with a combination of IgM, C3, and fibrinogen can be observed in LE, regardless of concurrent immunoglobulin deposition at the dermoepidermal junction. 2 Like cytoid bodies, the deposition of IgM and fibrinogen at the dermoepidermal junction may be regarded as byproducts of nonspecific interface dermatitis but may also be DIF patterns observed in LE. In one study, IgM deposition was the most frequent singlet immunoglobulin DIF pattern observed in cutaneous LE.…”

“…Again, the photodermatosis presented earlier than expected for patients with BS, at age 7 months. 2 Other important immunohistologic data were provided in the cases reviewed. DIF positivity was reported in 2 previous cases: Dicken et al reported cytoid bodies, which stained positively for IgG, IgM, C3, and fibrin along with weak deposition of fibrinogen at the dermoepidermal junction.…”

“…1 Since that time, other cases of BS have been described in the literature, all demonstrating 3 cardinal features-erythematous telangiectasias of the face, sun sensitivity, and stunted growth. 2 Skin lesions in BS are described as ''lupus like,'' in that their distribution and morphology are similar to the acute cutaneous manifestations of systemic lupus erythematosus (SLE). Dermatopathologic findings in BS remain poorly defined.…”