The clinical aspect of delayed development in the children with copy number variations

Abstract

Microarray-based comparative genomic hybridization (array CGH) has been widely adopted as a valuable clinical diagnostic test for children with delayed development. Bradley P. Coe et al. suggested copy number variants (CNVs) are associated with many neurocognitive disorders. Hence, overall development was measured between two groups divided by array CGH results. A retrospective chart review was done in 42 children who underwent array CGH after visiting PM&R Department outpatient clinic with delayed development as chief complaints. Children were evaluated for Denver Developmental Screening Test (DDST), Sequenced Language Scale for Infants (SELSI)/Preschool Receptive-Expressive Language Scale (PRES). A Mann-Whitney U test was conducted to determine statistical differences of Developmental Quotient (DQ), Receptive Language Quotient (RLQ) and Expressive Language Quotient (ELQ) between two groups: 14 children with CNVs and 28 children without CNVs. DDST showed that personal social and language DQ were higher and fine motor and gross motor were lower in CNV (+) group than in CNV (−) group, but the difference was not statistically significant. All 22 children who underwent SELSI or PRES showed delayed language in all domains and RLQ and ELQ were higher in CNV (+) group than in CNV (−) group and the difference was statistically significant for ELQ ( P < 0.05). In the CNV (+) group, ELQ was assessed higher than RLQ; In the CNV (−) group, ELQ was assessed lower than RLQ, but statistical significance was not observed in both inter-group. DQ in all domains was not significantly lower in children with CNV compared to children without CNV. However, tendency of milder delay of ELQ was observed in children with CNV. Active detection of genomic imbalance could play some vital role in assessing development aspect in children with delayed development.