[Familial presentation of microdeletion and inverted microduplication with array-CGH]

INTRODUCTION. Over the years the field of genetics has advanced significantly. Following the polymerase chain reaction and mass sequencing techniques, the array-CGH technique (comparative genomic hybridization) has helped to improve genetic procedures. A resolution of up to 200 kb is currently being accomplished in the human genome. CASE REPORTS. We report the case of two sisters with delays in developmental milestones and a characteristic phenotype with normal results from initial studies of the karyotype and subtelomeric regions. Array-CGH was later used to detect a deletion and duplication that were different in each of the sisters, this being the result of a balanced paternal translocation. In the two cases, despite being the result of the same translocation, the genetic and phenotype expression were different. CONCLUSIONS. The precision achieved by means of array-CGH is making it possible to establish a correlation between minimum gains or losses of the genome and the clinical features. Chromosome 3 codes for genes that play a fundamental role in neurological development (contactins, neurotransmitter modulator proteins, etc.) and chromosome 10 codes for proteins involved in apoptosis and proteins regulating transcription. In the literature there have been reports of chromosome 3 deletion syndrome and monosomy 10. Likewise, there are also descriptions of rearrangements between these chromosomes in individuals from the same family. Nevertheless, we describe two cases of a family with a micro-deletion and an inverted microduplication, detected by means of array-CGH, that have not been reported to date. This technique can provide a diagnostic and prognostic approximation as regards development and offer genetic counselling.