Healthy carrier parents in partial 7 and 9 chromosome trisomy in two pediatric patients: Report cases at the Hospital para el Nio Poblano, Mexico

Two pediatric cases are reported in this study, a one year and five months old male patient with partial trisomy for the long arm of chromosome 9 due to chromosome segregation error in the father 46 XY, del (9q-)/46 XY dup (10q+), and a seven years old male patient with partial trisomy for the long arm of chromosome 7 due to chromosome segregation error in the mother 46 XX, ins (10; 7) (q21; q23q35) are described. The major abnormalities in both cases are reported and compared, where both syndromes have defects including central nervous system disorders as mental retardation, hypotonia, craniofacial anomalies, micrognatia, poor feeding and xyphoescoliosis.   Key words: Central nervous system, partial trisomy, translocation, chromosome, healthy carriers.