Phenotypic features of a microdeletion in chromosome band 20p13: A case report and review of the literature

BACKGROUND: 20p13 microdeletion syndrome has been reported to be associated with developmental delays, intellectual disability, epilepsy, and unspecific dysmorphic characteristics. However, only a few cases of 20p13 microdeletion have been described, and therefore its typical features and precise pathogenesis remain elusive. METHODS AND RESULTS: In this article, we report the case of a 9‐month‐old infant who presented with a large fontanelle, facial dysmorphism, and failure to thrive. Array‐comparative genomic hybridization (aCGH) analysis confirmed a 2.01‐Mb microdeletion in chromosome band 20p13 that involved SOX12 and NRSN2, both of which are considered paramount causative genes in patients with 20p13 microdeletion. To elucidate the typical features of 20p13 microdeletion, we further reviewed these previously reported cases and found that motor delay (90%) was the most common manifestation, followed by language delay (60%), abnormal digits (60%), mental retardation (50%), large fontanelle (50%), electroencephalography abnormalities (50%), and seizure (40%). CONCLUSION: This report highlights the potential of aCGH as a practical and powerful tool with which to detect submicroscopic chromosomal abnormalities in individuals presenting with a wide spectrum of phenotypes, ranging from facial dysmorphism to failure to thrive. Additionally, the literature review casts new light on the clinical features of 20p13 microdeletion.