CLINICAL REPORT Microdeletion of 12q24.31: Report of a Girl With Intellectual Disability, Stereotypies, Seizures and Facial Dysmorphisms Orazio Palumbo, 1 Pietro Palumbo, 1 Maurizio Delvecchio, 2 Teresa Palladino, 1 Raffaella Stallone, 1 Matteo Crisetti, 2 Leopoldo Zelante, 1 and Massimo Carella 1 * 1 Medical Genetics Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo (FG), Italy 2 Pediatrics Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo (FG), Italy Manuscript Received: 28 February 2014; Manuscript Accepted: 4 October 2014 We provide a detailed clinical and molecular characterization of an 11-year-old female patient presenting with neurodevelop- mental delay (NDD), intellectual disability (ID), seizures, ste- reotypies and dysmorphic features. Chromosomal microarrays analysis (CMA) detected a small, rare de novo deletion on chromosome 12q24.31 encompassing 31 protein-coding RefSeq genes and a microRNA. Phenotypic comparison with molecular- ly well-defined cases previously reported in the literature har- boring an overlapping 12q24.31 microdeletion indicate that these patients shared common clinical features including neuro- developmental delay, intellectual disability and behavioral prob- lems. Also, seizures and dysmorphic features are frequent and a consistent pattern was recognized. Since there are remarkable resemblance between the patient described here and at least another one previously reported, our report is provides support- ive evidence for the existence of an emerging syndrome caused by a microdeletion in 12q24.31. We propose a minimal region shared among patients contributing to the etiology of the com- mon clinical features observed suggesting as candidate, for the first time, the gene SETD1B which is a component of a histone methyltransferase complex. In addition, we speculate on the possible contributive role of the MIR4304 to some clinical features observed in our patient. Evaluation of more patients with well-characterized deletions within 12q24.31, as well as careful clinical assessment of them, is needed to corroborate our hypothesis, to perform a more detailed genotype-phenotype correlation and, finally, to fully delineate this emerging micro- deletion syndrome. Ó 2014 Wiley Periodicals, Inc. Key words: 12q24.31 microdeletion; chromosomal microarrays analysis; genotype-phenotype correlation INTRODUCTION Screening of the whole genome for submicroscopic abnormalities in patients with multiple congenital anomalies (MCAs), intellectual disability (ID) and dysmorphic features using new technologies, such as array comparative genomic hybridization (array-CGH) or single-nucleotide polymorphism (SNP) array, has increased the number of previously undescribed cytogenetics abnormalities [Shaw-Smith et al., 2004; Menten et al., 2006] leading to the identification of many novel microdeletion and microduplication syndromes [Weise et al., 2012]. However, the clinical presentation and/or candidate genes responsible for the respective phenotypes in many newly detected syndromes remain to be elucidated. We present a girl with neurodevelopmental delay (NDD), intel- lectual disability (ID), seizures, stereotypies, and distinctive facial traits in which SNP-array analysis disclosed a 1.66 Mb de novo deletion of chromosome 12q24.31. Also, we compared at clinical and molecular level our patient with previously reported cases harboring an overlapping microdeletion identified by high-resolu- tion techniques. How to Cite this Article: Palumbo O, Palumbo P, Delvecchio M, Palladino T, Stallone R, Crisetti M, Zelante L, Carella M. 2015. Microdeletion of 12q24.31: Report of a girl with intellectual disability, stereotypies, seizures and facial dysmorphisms. Am J Med Genet Part A 167A:438–444. Conflict of interest: none Grant sponsor: Italian Ministry of Health; Grant number: Ricerca Corrente 2014; Grant sponsor: Progetto Operativo Nazionale PON 2007–2013 LAB; Grant number: GTP PON02_00619.  Correspondence to: Massimo Carella, PhD, Medical Genetics Unit, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo (FG), Italy. E-mail: m.carella@operapadrepio.it Article first published online in Wiley Online Library (wileyonlinelibrary.com): 26 November 2014 DOI 10.1002/ajmg.a.36872 Ó 2014 Wiley Periodicals, Inc. 438