American Journal of Medical Genetics 139A:231–233 (2005) Research Letter Investigation of Patients With Mental Retardation and Dysmorphic Features Using Comparative Genomic

For a number of years we have used high resolution meta-phase comparative genomic hybridization (CGH, referred to as HR-CGH in our prior papers) for detection of cryptic chromo-somal imbalances in patients with mental retardation and dysmorphic features. Although this technique detects imbal-ances in as many as 12 % of patients, additional diagnoses can be obtained if CGH is combined with subtelomeric FISH analysis [Kirchhoff et al., 2004]. In this study, we set out to test the diagnostic yield of subtelomeric multiplex ligation-depen-dent probe amplification (MLPA) in patients already investi-gated by CGH. In this study, we present the CGH and subtelomeric MLPA results of 258 patients with mental retardation and dys-morphic features. Introduction of a newmethod in a diagnostic routine setting requires careful consideration regardin