L'anémie de Fanconi : aspects cellulaires et moléculaires

[Fanconi anemia: report of a new case]

La maladie de Fanconi ou l'anémie de Fanconi (AF) est une maladie génétique rare à transmission autosomique récessive. Elle est marquée par une hétérogénéité phénotypique. Certains symptômes et notamment la triade classique faite d'une petite taille, d'un syndrome malformatif varié et parfois discret et d'une insuffisance médullaire d'apparition précoce, doivent faire évoquer le diagnostic. Nous rapportons le cas d'un enfant âgé de sept ans, suivi et traité pour une luxation congénitale des hanches, qui présentait une pancytopénie avec à l'examen clinique on note un faciès dysmorphique triangulaire, une duplication du pouce droit, une surélévation de l’épaule gauche et un retard staturo-pondéral.

HSCT for Fanconi anemia in children: factors that influence early and late results

Fanconi anemia (FA) is a rare autosomal recessive disease characterized by congenital abnormalities, cancer predisposition and progressive BM failure. FA patients present spontaneous and induced chromosome breakage. Hematopoietic SCT (HSCT) represents the unique therapeutic option to restore normal hematopoiesis when marrow failure or clonal hematopoietic abnormality occurs. Conventional myeloablative conditioning regimen, especially including a high dose of irradiation, appeared strongly toxic for FA patients. Then, reduced-intensity conditioning regimens were developed successfully for those patients. However, TRM still remained higher than for other HSCT indications. The development of fludarabine containing a non-myeloablative conditioning regimen appears to be a major progress. Long-term follow-up is absolutely necessary.

DNA damage and repair: from molecular mechanisms to health implications

DNA is subjected to several modifications, resulting from endogenous and exogenous sources. The cell has developed a network of complementary DNA-repair mechanisms, and in the human genome, >130 genes have been found to be involved. Knowledge about the basic mechanisms for DNA repair has revealed an unexpected complexity, with overlapping specificity within the same pathway, as well as extensive functional interactions between proteins involved in repair pathways. Unrepaired or improperly repaired DNA lesions have serious potential consequences for the cell, leading to genomic instability and deregulation of cellular functions. A number of disorders or syndromes, including several cancer predispositions and accelerated aging, are linked to an inherited defect in one of the DNA-repair pathways. Genomic instability, a characteristic of most human malignancies, can also arise from acquired defects in DNA repair, and the specific pathway affected is predictive of types of mutations, tumor drug sensitivity, and treatment outcome. Although DNA repair has received little attention as a determinant of drug sensitivity, emerging knowledge of mutations and polymorphisms in key human DNA-repair genes may provide a rational basis for improved strategies for therapeutic interventions on a number of tumors and degenerative disorders.