Korean J Pediatr.  2017 Sep;60(9):282-289. 10.3345/kjp.2017.60.9.282.

Application of array comparative genomic hybridization in Korean children under 6 years old with global developmental delay

• Lee KY
• Shin E

• KMID: 2390496
• DOI: http://doi.org/10.3345/kjp.2017.60.9.282

Abstract

PURPOSE
Recent advancements in molecular techniques have greatly contributed to the discovery of genetic causes of unexplained developmental delay. Here, we describe the results of array comparative genomic hybridization (CGH) and the clinical features of 27 patients with global developmental delay.
METHODS
We included 27 children who fulfilled the following criteria: Korean children under 6 years with global developmental delay; children who had at least one or more physical or neurological problem other than global developmental delay; and patients in whom both array CGH and G-banded karyotyping tests were performed.
RESULTS
Fifteen male and 12 female patients with a mean age of 29.3±17.6 months were included. The most common physical and neurological abnormalities were facial dysmorphism (n=16), epilepsy (n=7), and hypotonia (n=7). Pathogenic copy number variation results were observed in 4 patients (14.8%): 18.73 Mb dup(2)(p24.2p25.3) and 1.62 Mb del(20p13) (patient 1); 22.31 Mb dup(2) (p22.3p25.1) and 4.01 Mb dup(2)(p21p22.1) (patient 2); 12.08 Mb del(4)(q22.1q24) (patient 3); and 1.19 Mb del(1)(q21.1) (patient 4). One patient (3.7%) displayed a variant of uncertain significance. Four patients (14.8%) displayed discordance between G-banded karyotyping and array CGH results. Among patients with normal array CGH results, 4 (16%) revealed brain anomalies such as schizencephaly and hydranencephaly. One patient was diagnosed with Rett syndrome and one with Möbius syndrome.
CONCLUSION
As chromosomal microarray can elucidate the cause of previously unexplained developmental delay, it should be considered as a first-tier cytogenetic diagnostic test for children with unexplained developmental delay.

Keyword

Comparative genomic hybridization; Developmental disabilities; Child; Karyotyping

MeSH Terms

Brain
Child*
Comparative Genomic Hybridization*
Cytogenetics
Developmental Disabilities
Diagnostic Tests, Routine
Epilepsy
Female
Humans
Hydranencephaly
Karyotyping
Male
Muscle Hypotonia
Rett Syndrome
Schizencephaly