An instructive case of an 8-year-old boy with intellectual disability.

A child with global developmental delay sparing motor skills evolving into later intellectual disability with a consistently normal neuromuscular examination was discovered to have a dystrophin specific mutation in the 3' end of the gene. The deletion in the DMD gene was unsuspected and discovered through array comparative genomic hybridization and confirmed on polymerase chain reaction analysis. This case shows a central nervous system-specific and restrictive phenotype for a disorder that is conceptualized as being progressively neuromuscular in clinical expression.

Development of a high-density pericentromeric region BAC clone set for the detection and characterization of small supernumerary marker chromosomes by array CGH.

Purpose: Small supernumerary marker chromosomes are centric chromosomal segments that, by definition, cannot be characterized unambiguously by conventional chromosome banding. Marker chromosomes are of particular interest in clinical cytogenetics because they are nearly 10 times more frequent in individuals with mental retardation (0.426%) than in the normal population (0.

Detection of low-level mosaicism by array CGH in routine diagnostic specimens.

The advent of microarray-based comparative genomic hybridization (array CGH) promises to revolutionize clinical cytogenetics because of its ability to rapidly screen the genome at an unprecedented resolution. Yet, the ability of array CGH to detect and evaluate low-level mosaicism is not known. Our laboratory has analyzed over 3,600 clinical cases with the SignatureChip which we developed for the detection of microdeletions, microduplications, aneuploidy, unbalanced translocations, and subtelomeric and pericentromeric copy number alterations.

Use of targeted array-based CGH for the clinical diagnosis of chromosomal imbalance: is less more?

Chromosome analysis is an important component to the diagnosis of congenital anomalies, developmental delay, and mental retardation. Routine chromosome analysis identifies aneuploidy and structural rearrangements greater than 5 Mb but cannot identify abnormalities of the telomeric regions or microdeletions reliably. Molecular cytogenetic techniques were developed to overcome these limitations.