We present here, a case of a neonate with an unbalanced chromosomal translocation due to a maternal chromosomal translocation carriage that resulted in the presence of trisomy 9p combined with a partial trisomy 12p. Karyotype analysis was performed using conventional cytogenetic chromosomal analysis using the GTG-banding technique. The mother was a carrier of a balanced chromosomal translocation of 46, XX, t(9;12)(q13;p11.2), that resulted in an unbalanced translocation of the offspring, who had a karyotype 47, XX, +der(9)t(9;12)(q13;p11.2)dmat, featuring a combined trisomy of 9q13→9pter region and 12p11.2→12pter region. Clinical phenotype of the infant included cephalo-facial deformity, growth retardation, hypertonia, opisthotonus, laryngeal wheezing, foot deformity, and congenital heart disease.
Keywords: cytogenetic analysis; partial trisomy 12p; trisomy 9p; unbalanced chromosomal translocation.