A New Case of a Complex Small Supernumerary Marker Chromosome: A Der(9)t(7;9)(p22;q22) due to a Maternal Balanced Rearrangement.

Complex small supernumerary marker chromosomes (sSMCs) constitute one of the smallest subsets within the patients with an sSMC. Complex sSMCs consist of chromosomal material derived from more than one chromosome, for example, the derivative der(22)t(11;22)(q23;q11.2) in Emanuel syndrome. Here, a yet unreported case of a complex sSMC formed due to a t(7;9)(p22;q22)mat is presented.