Complex chromosome rearrangements (CCR) are rare structural chromosome aberrations that can be found in patients with phenotypic abnormalities or in phenotypically normal patients presenting, however, recurrent miscarriages or infertility. Conventional karyotype generally allows their identification. However, molecular cytogenetic methods can reveal subtle rearrangements. We report, here, the identification of an unbalanced maternally inherited CCR in a boy with multiple congenital malformations and delayed development. High-resolution karyotype completed by molecular cytogenetic prompted us to precise the rearrangements. The healthy mother was found to carry a balanced de novo CCR that implicates four chromosomes (8, 10, 11 and 16), six breakpoints, three translocations and an insertion. The malsegregation of this CCR had led, in her son, to partial 10p12.3 to 10p14 deletion, a chromosomal region associated with the DiGeorge like phenotype.