RESUMO
The use of new technologies in the routine diagnosis of constitutional abnormalities, such as high-resolution chromosomal microarray and next-generation sequencing, has unmasked new mechanisms for generating structural variation of the human genome. For example, complex chromosome rearrangements can originate by a chromosome catastrophe phenomenon in which numerous genomic rearrangements are apparently acquired in a single catastrophic event. This phenomenon is named chromoanagenesis (from the Greek "chromo" for chromosome and "anagenesis" for rebirth). Herein, we report 2 cases of genomic chaos detected at prenatal diagnosis. The terms "chromothripsis" and "chromoanasynthesis" and the challenge of genetic counseling are discussed.
Assuntos
Pontos de Quebra do Cromossomo , Cromotripsia , Rearranjo Gênico , Genoma Humano , Diagnóstico Pré-Natal/métodos , Aborto Eugênico , Adulto , Hibridização Genômica Comparativa , Variações do Número de Cópias de DNA , Feminino , Feto , Aconselhamento Genético/ética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cariotipagem/métodos , Masculino , GravidezRESUMO
1q44 deletion is a rare syndrome associated with facial dysmorphism and developmental delay, in particular related with expressive speech, seizures, and hypotonia (ORPHA:238769). Until today, the distinct genetic causes for the different symptoms remain not entirely clear. We present a patient with a 2.3-Mb 1q44 deletion, including AKT3, ZBTB18, and HNRNPU, who shows microcephaly, developmental delay, abnormal corpus callosum, and seizures. The genetic findings in this case and a review of the literature spotlight a region between 243 Mb and 245 Mb on chromosome 1q related to the genesis of the typical symptoms of 1q44 deletion.