A Novel Intronic KMT2D Variant as a Cause of Kabuki Syndrome: A Case Report

Abstract

Erica Aristizábal,1 Lorena Diaz-Ordóñez,1 Estephania Candelo,1,2 Harry Pachajoa1,2 1Center for Research on Congenital Anomalies and Rare Diseases (CIACER), Department of Basic Medical Sciences, Universidad Icesi, Cali, Valle del Cauca, Colombia; 2Fundación Valle del Lili, Cali, Valle del Cauca, ColombiaCorrespondence: Lorena Diaz-OrdóñezCenter for Research on Congenital Anomalies and Rare Diseases (CIACER), Department of Basic Medical Sciences, L Building, Zip: 760031, Universidad Icesi, Cali, ColombiaTel [phone] Ext: 8542Email [email protected]: Kabuki syndrome (KS) is an autosomal dominant genetic disorder in which most cases are caused by de novo mutations. KS type 1 is caused by mutations in KMT2D (OMIM: #147920) and is more common. KS type 2 is caused by mutations in KDM6A (OMIM: #300867). Both genes encode proteins that modify histones and are involved in epigenetic regulation. The enzyme histone-lysine N-methyltransferase 2D, the product of KMT2D, is expressed in most adult tissues and is essential for early embryonic development. The main clinical manifestations of KS include dysmorphic facial features, such as elongated palpebral fissures, eversion of the lateral third of the lower eyelids, and short nasal columella with a broad and depressed nasal tip. Additionally, patients also present with skeletal abnormalities, dermatoglyphic features, mild-to-moderate intellectual disability, hearing loss, and postnatal growth deficiency. We describe an 11-year-old girl from Colombia, who presented with characteristic clinical signs of KS. Genetic studies showed a KMT2D intronic variant (KMT2D NM_003482.3: c.511‐2A> T) as a cause of KS.Keywords: Kabuki syndrome, coloboma, rare disease, RNA splicing, sensorineural hearing loss

Keywords

• kabuki syndrome
• coloboma
• rare disease
• rna splicing
• sensorineural hearing loss