Reciprocal Chromosomal Translocations, 47,XY, t(11;14) +der(14) t(11;14) (q25;q24.1), 46,XY,t(1;4) (q11-12;q11), 46,XY,t(6;9) (p21;q34) and 45,XY, der(13;15) (q10;q10). Four Mexican Pediatric Cases Report. J. Aparicio^1,6, M. Barrientos², M.L. Hurtado³, C. Gil^4,6, R. Ruiz⁵, W. San Martin⁴, C. Salinas⁷. 1) Dept Genetics,; 2) Endocrinology,; 3) Cytogenetics,; 4) Estomatology,; 5) Pediatrics, Hosp para el Nino Poblano, Puebla; 6) Estomatology, Benemerita Universidad Autonoma de Puebla, Mexico; 7) Estomatology and Genetics, univ of South Carolina, USA.
   INTRODUCTIÓN. The reciprocal translocations should not be in relation to fenotipical malformations, since there should not be DNA alteration. however, fenotipical malformations, mental retardation and neoplasic proceses have been reported.CLINICAL CASES. Pacient 1: An adolescent male with a fibro-osseous lesion of the jaws, a non familiar gigantiform cementoma, radiologically and histopathologically, with a flat fascies and minor phenotypic alterations. A de novo reciprocal translocation between chromosomes 1 and 4. Pacient 2: A 9 years male with mental retardation, facial malformations, polidactilia, hypertricosis, small genitalia and obesity, with a translocation, 46,xy,t(6;9). both parents with a normal cariotype. Pacient 3: A newborn male with partial trisomy of chromosome 14 (14q24) and a translocation t(11;14), with , lobar neumony, hidrocele, septicemia, interauricular septal defect, cleft palate and a dismorfic phenotipe. Patient 4: A 10 years male, with oligodoncy and hyperkinesis with a 45,xy,der(13;15). Has an affected carrier mother 45,xx der(13;15). CONCLUSIONS. some chromosomal translocations has been reported as primary etiological factor for different kind of clinical malformations and celular neoplasias. t(1;4), t(6;9), t(11;14) and t(13,15) has been thought to be in relation to cell lymphoma, leukemia and other kind of neoplasias, originating from pre-immune b-cells in the mantle zone of the primary follicles in secondary lymphoid organs. in b-prolymphocytic leukaemia, in plasma cell leukaemia, and in chronic lymphocytic leukaemia, in multiple myeloma and also in immunosupresion events. it is important to study such chromosmal translocations in afected children in order to get an earlier treatment for a better quality of life.