Microarray analysis in children with developmental disorder or epilepsy

Abstract

The technique of chromosomal microarray analysis identifies genetic imbalance. Evaluation of its diagnostic role in pediatrics is still underway. We describe our experience with chromosomal microarrays. We retrospectively reviewed the charts of children in the Sections of Neurology and Clinical Genetics at St. Christopher's Hospital for Children who had undergone microarray analysis between 2006 and 2009. Collected data included age, sex, and the presence of mental retardation, developmental delay, autism, learning disability, hypotonia, dysmorphic features, and epilepsy, and the use of microarray technique. Statistical analysis was performed using SPSS. There were 82 children (mean age ± S.D., 5.7 ± 5 years), including 45 (55%) boys and 37 (45%) girls. All patients exhibited a normal karyotype. Microarray analysis produced abnormal results in 20 (23.5%). Deletions comprised 74% of all abnormalities. Patients with ≥ 4 clinical variables demonstrated a 30.5% incidence of abnormal chromosomal microarray findings, compared with 8.7% of patients with ≤ 3 clinical variables (P = 0.039, χ(2) test). Logistic regression indicated that motor impairment (P = 0.039) and presence of epilepsy (P = 0.024) independently contributed to the model. The likelihood of an abnormal microarray result increased with the number of clinical abnormalities. Microarray analysis will likely become the diagnostic genetic test of choice in children with neurodevelopmental disorders or epilepsy.