Mental retardation occurs in 1-3% of the general population worldwide. In Czech Republic, about 3% of children are born annually with "major physical anomaly".
Previously published reports of chromosomal aberrations in cohorts of mentally retarded patients have shown that many small aberrations are overlooked by conventional cytogenetic methods, such as G/C banding. Instead, the higher resolution level array-based comparative genomic hybridization (array CGH) can reveal novel submicroscopic deletions/duplications.
Only four patients has been previously reported with a small interstitial deletions of band 12q24.31 (-q24.33) without other karyotypic anomalies (1)-(4). In this study a detailed clinical description, and molecular cytogenetic analysis of a patient with de novo 12q interstitial deletion is presented.
The Agilent´s Human Genome CGH Microarray 44K array revealed that subtelomere of 12q showed an interstitial hemizygous deletion: chr.12; 46XY, del (12)(q24.31). We offer comparison of our patient with the earlier described patients with respect to genes included in 12q24 deletions and phenotype.
Supporting data from ECARUCA and ISCA databases are also implemented into the discussion.