ODLURO syndrome: personal experience and review of the literature

Introduction: The O’Donnell–Luria–Rodan (ODLURO) syndrome, caused by heterozygous mutation in the lysine N-methyltransferase2E (KMT2E) gene in chromosome 7q22, has been recently described. Mutation of KMT2E produces a protein-truncating variant gene that may be responsible for both developmental delay and intellectual disability disorders commonly defined by an Intelligence Quotient < 70 and usually unspecific pathologic brain features demonstrated by brain Magnetic Resonance imaging. The symptoms of ODLURO syndrome include variably developmental and speech delay, autism, seizures, hypotonia, and dysmorphic features. The aim of the study is to search for correlation between this specific gene mutation and clinical/radiological features, trying to provide new insights in this recently described pathological condition. Methods: We reviewed the 38 cases collected by O’Donnel-Luria et al., adding three cases of a familial heterozygosis novel mutation in KMT2E gene; different degrees of neurological disorder, subtle dysmorphic features, intellectual disability, epilepsy, and various brain Magnetic Resonance features are described. Results: Magnetic Resonance data were integrated by genetic analysis and clinical features. Brain Magnetic Resonance study of our patients confirmed peculiar pathologic features previously reported in ODLURO syndrome; cerebellar dysplasia was identified in one of them. All 3 patients had epilepsy, intellectual disability, and mild dysmorphisms. Conclusions: Our study adds 3 new patients genetically, clinically, and radiologically evaluated to the ODLURO syndrome case series. While CC hypoplasia and widening of subarachnoid spaces are already reported in literature, we document for the first time the presence of cerebellar dysplasia in ODLURO syndrome. We also highlight the extremely low IQ value and the presence of epilepsy in all 3 patients.