Introduction: Pallister-Killian syndrome (PKS) is a rare multiple congenital anomaly/intellectual disability syndrome caused by tissue-restricted, mosaic tetrasomy 12p. The most common signs are facial dysmorphism, rhizomelic shortening of the extremities, pigmentary mosaic in skin; craniofacial manifestations include a \u27\u27coarse\u27\u27 face with a flat profile and a wide forehead with sparse scalp hair in temporofrontal regions.Objective: To describe the karyotype and clinical manifestations in patients with suspected Pallister Killian Syndrome.Methods: Chromosomal studies were performed using conventional techniques in peripheral blood samples and skin samples in two patients, and a sample of amniotic fluid from a 17.3-week pregnant woman due to positive markers in the ultrasound. Peripheral blood cultures showed normal karyotypes in patients 1 and 2. Results: The fibroblast culture karyotypes of the patients studied reflected: Case 1: 47, XY+ i (12p) [8]/46 XY [10], Case 2:47, XY+ i (12p) (p10) [11] y Case 3: 47, XX + i (12p) [7]/46, XX [5] respectively. Conclusions:The SPK detected by conventional cytogenetics allowed a conclusive diagnosis in skin samples, despite the lack of molecular cytogenetic techniques, in those cases where chromosomal aberrations are restricted to a certain group of cells
