Partial trisomy 17q and partial monosomy 20q in a boy with craniosynostosis.

Craniosynostosis is defined as a premature fusion of at least one cranial suture, which can be accompanied by other findings. Of syndromic cases, 14-22% have been associated with chromosomal rearrangements. This report describes a Brazilian boy with syndromic craniosynostosis who also presented with intellectual disability, microcephaly, frontal bossing, bitemporal narrowing, short neck, syndactyly, and cardiac defects. Chromosome banding showed an apparently normal male karyotype. Subsequent chromosomal microarray analysis (CMA) using the Affymetrix CytoScan 750 K Array showed a duplication of 2.1 Mb on chromosome 17q and a deletion of 1.4 Mb on chromosome 20q. The data suggested an unbalanced translocation, which was confirmed by fluorescence in-situ hybridization analysis (FISH). While there are several reports in the literature of chromosome 17q duplication syndrome accompanied by partial monosomies of other chromosomes, this is the first case featuring partial monosomy of 20q. The patient́s phenotype is generally consistent with 17q duplication syndrome, however craniosynostosis has rarely been associated with this chromosomal anomaly.

A Balanced Reciprocal Translocation t(2;9)(p25;q13) Disrupting the LINC00299 Gene in a Patient with Intellectual Disability.

Long intergenic noncoding RNAs (lincRNAs) are a class of noncoding RNAs implicated in several biological processes. LincRNA 299 (LINC00299) maps to 2p25.1 and its function is still unknown. However, this gene has been proposed as a candidate for intellectual disability (ID) in a patient with a balanced translocation where the breakpoint disrupted its ORF. Here, we describe a new case of LINC00299 disruption associated with ID. The individual, a 42-year-old woman, was referred to the clinical geneticist because of her son who had severe syndromic ID. G-banding and chromosomal microarray analysis were performed. Karyotyping of the boy revealed an extranumerary derivative chromosome identified as an unbalanced translocation between chromosomes 2 and 9 of maternal origin. The mother's karyotype showed a balanced translocation 46,XX,t(2;9)(p25;q13). Chromosomal microarray indicated a disruption of LINC00299. These data corroborate the role of LINC00299 as a causative gene for ID and broadens the spectrum of LINC00299-related phenotypes.