Intragenic Deletion of the <b><i>ZMYND11</i></b> Gene in 10p15.3 is Associated with Developmental Delay Phenotype: A Case Report

Submicroscopic 10p15.3 microdeletions were previously reported to be associated with developmental delay, and the smallest region of overlap of 10p15.3 deletion including DIP2C and ZMYND11 was defined. Moreover, pathogenic ZMYND11 truncating variants were subsequently identified in a cohort of patients with developmental delay. Of interest, patients harboring 10p15.3 microdeletions or pathogenic ZMYND11 truncating variants share similar clinical features including hypotonia, intellectual disability, facial dysmorphisms, speech and motor delays, seizures, and significant behavioral problems. Only 1 patient with whole ZMYND11 gene deletion was recorded, and no intragenic ZMYND11 deletion was reported up to date. Here, we describe a 7-year-old boy with developmental delay, carrying the smallest de novo 10p15.3 microdeletion, harboring the 5'UTR and the first 2 exons of ZMYND11. Taken together, our report contributes to expand the clinical and mutational spectrum of ZMYND11 and confirms haploinsufficiency as the underlying disease mechanism.