Cytogenetic and Array-CGH Characterization of a Simple Case of Reciprocal t(3;10) Translocation Reveals a Hidden Deletion at 5q12

Chromosome deletions, including band 5q12, have rarely been reported and have been associated with a wide range of clinical manifestations, such as postnatal growth retardation, intellectual disability, hyperactivity, nonspecific ocular defects, facial dysmorphism, and epilepsy. In this study, we describe for the first time a child with growth retardation in which we identified a balanced t(3;10) translocation by conventional cytogenetic analysis in addition to an 8.6 Mb 5q12 deletion through array-CGH. Our results show that the phenotypic abnormalities of a case that had been interpreted as balanced by conventional cytogenetics are mainly due to a cryptic deletion, highlighting the need for molecular investigation in subjects with an abnormal phenotype before assuming the cause is an apparently simple cytogenetic rearrangement. Finally, we identify PDE4D and PIK3R1 genes as the two major candidates responsible for the clinical features expressed in our patient.

Automated summary

This study reports a child with growth retardation identified through conventional cytogenetic analysis and array-CGH to have a balanced translocation and a 5q12 deletion. The findings suggest that cryptic deletions in chromosomes may lead to phenotypic abnormalities, emphasizing the importance of molecular investigation in cases of abnormal phenotype before assuming a simple cytogenetic rearrangement. Additionally, PDE4D and PIK3R1 genes are identified as potential candidates responsible for the clinical features in the patient.