Array-Based Comparative Genomic Hybridization for the Detection of Genetic Aberrations in Cases of Congenital Anomalies and Developmental Delays
ML Petras, GJ Tsongalis. Dartmouth-Hitchcock Medical Center, Lebanon, NH
Background: Traditionally, cytogenetic studies have been the main method for etiologic investigation of congenital anomalies, developmental delay, and mental retardation. High-resolution (5 megabases or greater) cytogenetic studies and fluorescence in situ hybridization (FISH) techniques have been the mainstay of these investigations; however, despite advances in techniques, the majority of cases go unresolved as to finding a responsible genetic abnormality. Array-based comparative genomic hybridization has become the new standard for analyzing the genome for microscopic and submicroscopic structural chromosomal imbalances and is able to detect DNA dosage alterations as small as a few thousand base pairs. Increased detection of genetic abnormalities leads to improved clinical diagnosis and subsequent patient management.
Design: A series of 642 cases of patients with developmental delay, dysmorphic features, seizure and metabolic disorders, autism and/or other developmental anomalies were sent for microarray analysis to Signature Genomics Laboratories, LLC, Spokane, WA. Peripheral blood samples were used in all cases. Samples underwent testing via either bacterial artificial chromosome (BAC) clones or oligonucleotide probes. All abnormalities were confirmed by FISH.
Results: Of these 642 patient samples, 106 cases demonstrated an abnormal result (a hit rate of 16.5%). The abnormal cases included both those with and without a known cytogenetic abnormality, thus improving detection rate of genetic anomalies. Turn-around-time for results averaged 6 days.
Conclusions: The use of array-based comparative genomic hybridization allows for an increase in the detection of cytogenetic anomalies in patients with developmental delay, dysmorphic features, seizure and metabolic disorders, autism and/or other developmental anomalies. This technique identifies a greater number of smaller chromosomal structural anomalies.
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 233, Wednesday Afternoon