A Novel 1.13 Mb Interstitial Duplication at 19q13.32 Causing Developmental Delay and Microcephaly in a Pediatric Patient: the First Asian Case Report

Only 6 patients with partial trisomy of the long arm of chromosome 19 (19q), caused by direct interstitial duplications, have been reported until today. Herein, we report a pediatric patient with a novel 1.13 Mb direct interstitial duplication within 19q13.32, which is the smallest fragment affected so far. A five-year old Korean boy of healthy parents presented with microcephaly, growth retardation, developmental delay, and craniofacial dysmorphism. Even though G-banded chromosome analysis at resolution of 550-band revealed normal karyotype, duplication of 1.13 Mb fragment within 19q13.32 was detected by array comparative genomic hybridization. Comparing with previously reported patients with pure duplication involving 19q as a sole chromosomal abnormality, our case showed the smallest duplication segment with relatively mild degree of clinical features. Our present case might serve as the landmark case among patients with 19q duplication for genotype-phenotype correlation study and further identification of critical region for 19q duplication abnormalities.