Partial trisomy of chromosome 18q11.2-q12: A case report

Abstract

= Abstract = Edwards syndrome, also called trisomy 18, is one of the most common autosomal anomalies. The survival rate of patients with Edwards syndrome is very low and its characteristic findings include cardiac malformations, mental retardation, growth retardation, specific craniofacial anomalies, clenched hands, rocker-bottom feet, and omphalocele. Compared with the classic Edwards syndrome, the symptom of partial duplication of chromosome 18 is relatively mild with a good prognosis. We report the case of a baby with partial duplication 18q11.2-q12. The characteristic phenotype features of Edwards syndrome were observed in the patient. However, the symptom was milder than the typical Edwards syndrome. At present, we can expect better prognosis for this patient. (Korean J Pediatr 2009;52:1171-1174

A non-syndromic intellectual disability associated with a de novo microdeletion at 7q and 18p, microduplication at Xp, and 18q partial trisomy detected using chromosomal microarray analysis approach

“…On the other hand, the most relevant alteration observed was a de novo 18q partial trisomy with 40% mosaicism. The degree of clinical manifestations in a patient who presents partial trisomy of chromosome 18 is variable, generally include a relatively mild phenotype with a high survival rate [ 1 ]. In the partial trisomy form, only a segment of the chromosome 18q is present in triplicate, often resulting from a balanced translocation or an inversion carried by one parent.…”

“…Chromosome abnormalities that segregate with a disease phenotype can facilitate the identification of disease loci and genes. The relationship between chromosome 18 anomalies with severe intellectual disability (ID) has attracted the attention of cytogeneticists worldwide [ 1 ]. Moreover, the partial trisomy of the chromosome 18 is a rare genetic chromosomal syndrome, corresponding to a variant and less severe form of Edwards’s Syndrome (OMIM 300484).…”

“…Eighty percent of the cases of Edwards’s Syndrome present full trisomy, the other 20% present mosaic or partial 18 trisomy [ 1 ]. After birth, mosaic chromosomal abnormalities are essentially identified among individuals with phenotypic manifestation of recognizable aneuploidy (chromosomal) syndromes.…”