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.

Chromosomal abnormalities in childhood acute nonlymphocytic leukemia (M4).

A new reciprocal, apparently balanced translocation between chromosomes 7 and 22, i.e., t(7;22)(p22;q13), in association with inv(16)(p13q22) in a child with acute nonlymphocytic leukemia (M4) is reported. Five percent of her bone marrow cells contained both of these aberrations while 90% of her cells have the pericentric inversion of chromosome 16 as the sole abnormality. A clonal evolution of the unusual cell line may be associated with atypical clinical presentation. The presence of inversion 16 in adults has a better prognosis as compared with children. A concise review on the cytogenetic findings in children with ANLL(M4) is also provided.