Molecular characterization of a complex translocation in a newborn infant.

A newborn infant was referred because of low-set ears, mild downward slant of the palpebral fissures, micrognathia with high-arched palate, a flat midface, small mouth, and thin upper lip with cupid bow configuration. To some extent her cry resembled that associated with cri du chat syndrome. Cytogenetic findings with G- and Q-banding alone failed to characterize precisely the complex translocations. By the chromosome in situ suppression (CISS) hybridization technique using whole chromosome specific probes, a complex 4 breakpoint rearrangement involving both arms of a single chromosome 1 with the long arms of chromosomes 5 and 11 was disclosed, i.e., 46,XX, der(1),t(1;5) t(1;11) (5qter-->5q31::1p31.3-->1q44::11q23-->11 qter;5pter-->5q31::1p31.3-->1pter;11pter-- >11q 23::1q44-->1qter). Gene deregulation and position effect may explain the multiple anomalies in individuals with apparently balanced translocations. The molecular characterization of such cytogenetically balanced translocations may shed some light towards unveiling the clinical consequences associated with aberrations which are presumably balanced.