RESUMEN
This article describes studies of two unrelated patients, aged near 2 years, with leukocyte granulation abnormalities similar to those presented in the Chediak-Higashi Syndrome(CHS). Both patients showed dermatologic manifestations characterized by hypopigmentation of the hair and skin. The cytological and cytochemical study of the peripheral blood leukocytes demonstrated giant abnormal granules with lisosomal content presentd in neutrophils, eosinophils and monocytes. The mononuclear cells displayed one large azurophil granule. The cytochemical functional study of neutrophils showed normal nitroblue-tetrazolium reduction test. The immunological status of the patients were made and in patient 1 was detected a low number of T helper lymphocytes and a maintenance of lymphocytes in continuous cell culture for five weeks without addition of external growth factor. These findings with clinical manifestations permited to establish the CHS, in these cases.