LAUSR

Complex chromosomal rearrangements (CCRs) are rare structural chromosomal aberrations characterized by more than two breakpoints in one or more chromosomes, with interas well as intra-chromosomal insertions of single segments [1, 2]. These abnormalities may involve distal segments causing mainly reciprocal translocations and/or interstitial segments leading predominantly to insertions, inversions, deletions, or duplications [3, 4]. Notably, CCRs are rare structural rearrangements which can be balanced or unbalanced. The phenotype of CCR carriers varies from normal to mild to severely affected with congenital abnormalities and/or intellectual disability. The likelihood of an abnormal phenotype increases with the number of breakpoints associated with an apparently balanced CCR [5–7]. Till date, more than 250 CCR cases involving three or more chromosomes have been reported, and most of them were de novo. While almost all unbalanced CCRs lead to serious clinical problems for the carrier, balanced CCRsmay go unrecognized until the affected carriers is diagnosed with a severe reproductive impairment. The latter is due to meiotic disturbance and/ or chromosomal imbalances in the resulting gametes [8–10]. Thus, there is a high risk of miscarriage or having live born children with unbalanced chromosomal rearrangements due to the CCR. Often, it is not possible to distinguish balanced from unbalanced CCRs only by banding cytogenetics. Advanced techniques like fluorescence in situ hybridization (FISH) may also not be conclusive in all cases [11–14]. However, array comparative genomic hybridization (aCGH) studies have been shown to be suited to identify cryptic CCRs [1, 15, 16]. Here, we present an adult male with minor facial dysmorphism, speech impairment, and a history of previous unsuccessful pregnancy in the partnership. A CCR with cryptic imbalances of about 1.5 megabase pairs (Mbp) was identified.