The first Korean case of 2p15p16.1 microdeletion syndrome, characterized by facial dysmorphism, developmental delay, and congenital hypothyroidism

ABSTRACT

The microdeletion syndrome of chromosome 2p15p16.1 (MIM: 612513) is an extremely rare contiguous gene deletion syndrome. Microdeletions of varying sizes in the 2p15-16.1 region are associated with developmental delay, intellectual disability, autism spectrum disorder, hypotonia, and craniofacial dysmorphism. Previous studies have identified two critical regions: the proximal 2p15 and distal 2p16.1 regions. BCL11A, PAPOLG, and REL genes play crucial roles in patients with 2p16.1 microdeletion. To our knowledge, only 39 patients have been reported as having 2p15p16.1 microdeletion syndrome. Here, we present another patient with 2p15p16.1 microdeletion syndrome. A nine-month-old boy was referred to our clinic for the psychomotor delay, facial dysmorphism, and congenital hypothyroidism. During his follow-up visits, he was diagnosed with global developmental delay, intellectual disability, abnormal behavior, hypotonia, microcephaly, and abnormal electroencephalography. Using a chromosomal microarray for genetic analysis, a novel, de novo, 622 kb microdeletion of 2p16.1 was identified as one of the critical regions of the 2p15p16.1 microdeletion syndrome. This is the first case of its kind in Korea. We have discussed our case and literature reviews to clarify the relationship between the genes involved and clinical phenotypes in 2p15p16.1 microdeletion syndrome.