[1] IMSS, La Raza Med Ctr, Dept Pediat Hematol, Mexico City, DF, Mexico
[2] IMSS, Siglo XXI Med Ctr, Med Specialties Hosp, Dept Hematol, Puebla, Mexico
[3] IMSS, Siglo XXI Med Ctr, Pediat Hosp, Dept Hematol, Mexico City, DF, Mexico
[4] IMSS, Siglo XXI Med Ctr, Oncol Hosp, Oncol Res Unit, Mexico City, DF, Mexico
[5] IMSS, Gabriel Mancera Hosp, Dept Pediat, Mexico City, DF, Mexico
[6] IMSS, La Raza Med Ctr, Umbil Cord Blood Bank, Dept Pediat Hematol, Mexico City, DF, Mexico