Research paper Identification of mutations in Colombian patients affected with Fabry disease Alfredo Uribe a, ⁎ ,1 , Heidi Eliana Mateus b,1 , Juan Carlos Prieto c , Maria Fernanda Palacios c , Sandra Yaneth Ospina b , Gabriela Pasqualim d , Ursula da Silveira Matte d,e , Roberto Giugliani d,e a Centro de Investigaciones en Bioquímica (CIBI), Departamento de Ciencias Biológicas, Universidad de Los Andes, Carrera 1 No. 18° - 12, Bogotá, Colombia b Unidad de Genética, Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Carrera 24 N° 63C-69, Bogotá, Colombia c Instituto de Genética, Facultad de Medicina, Universidad Javeriana, Carrera 7 No. 40-62 Ed. 32, Bogotá, Colombia d Centro de Terapia Gênica, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, 2350, Porto Alegre, RS 90035-003, Brazil e Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, 2350, Porto Alegre, RS 90035-003, Brazil abstract article info Article history: Received 27 November 2014 Received in revised form 5 August 2015 Accepted 10 August 2015 Available online 18 August 2015 Keywords: α-galactosidase A Mutations GLA gene Lysosomal disorder Fabry Disease (FD) is an X-linked inborn error of glycosphingolipid catabolism, caused by a deficiency of the lisosomal α-galactosidase A (AGAL). The disorder leads to a vascular disease secondary to the involvement of kidney, heart and the central nervous system. The mutation analysis is a valuable tool for diagnosis and genetic counseling. Although more than 600 mutations have been identified, most mutations are private. Our objective was to describe the analysis of nine Colombian patients with Fabry disease by automated sequencing of the seven exons of the GLA gene. Two novel mutations were identified in two patients affected with the classical sub- type of FD, in addition to other 6 mutations previously reported. The present study confirms the heterogeneity of mutations in Fabry disease and the importance of molecular analysis for genetic counseling, female heterozy- gotes detection as well as therapeutic decisions. © 2015 Elsevier B.V. All rights reserved. 1. Introduction Fabry disease (FD; OMIM: 301500) is an X-linked lysosomal storage disorder caused by the deficiency of the enzyme alpha-galactosidase A (AGAL, EC 3.2.1.22) (Brady, 1967). This enzymatic defect leads to the sys- temic accumulation of glycosphingolipids (mainly globotriaosylceramide -GL3-) in blood vessels from the skin, kidney, heart and brain (Desnick et al., 2003). Today two main FD subtypes have been described. The first one, or “classical phenotype”, affects males who have a markedly reduced AGAL activity. In these patients the onset of disease occurs in childhood or adolescence and is characterized by acroparesthesias, angiokeratomas, corneal opacities, hypohydrosis and progressive vasculopathy of the kid- ney, heart, and central nervous system (Desnick and Brady, 2004). The second phenotype, or “milder”, has been described in patients with a higher residual AGAL activity and a later onset characterized by cardiac and renal symptoms (Nakao et al., 2003, 1995; Terryn et al., 2013). Due to the late appearance of symptoms in patients with milder FD, the prevalence of this phenotype seems to be higher in relation to patients with classical FD, whose incidence has been estimated to be between 1:40.000 to 1:117.000 male births, approximately (Lin et al., 2009; Meikle et al., 2006; Spada et al., 2006). Patients with FD can be diagnosed by evaluating AGAL activity in plasma or white blood cells, however this analysis often fails to distin- guish between Fabry heterozygotes with high residual AGAL activity and normal individuals. For this reason, mutation analyses are required to detect female heterozygotes, define genotype/phenotype correla- tions, and to make an accurate prenatal diagnosis and take therapeutic decisions (Yoshimitsu et al., 2011; Lukas et al., 2013). The genomic sequence of the GLA gene is 12 kb in length and contains 7 exons (OMIM: 300644). To date, more than 600 mutations have been described including missense, nonsense and splice-site mu- tations, as well as gene rearrangements (Ashley et al., 2001; Schirinzi et al., 2008; Shabbeer et al., 2006). Most of the described mutations are private (with some few exceptions found in several unrelated sub- jects) and are usually associated with modifications in CpG dinucleo- tides, known hotspots for the disease (Barker et al., 1984; Cooper and Youssoufian, 1988). In this study, we describe the first clinical and genetic analysis of nine Colombian FD patients. Direct sequencing of the complete GLA open reading frame revealed eight mutations, two new and six previously re- ported. Patients with the classical phenotype of FD were identified, Gene 574 (2015) 325–329 Abbreviations: FD, Fabry disease; AGAL, alpha-galactosidase A; GLA, alpha-galactosidase A gene; GL3, globotriaosylceramide; DBS, dried blood sample. ⁎ Corresponding author. E-mail addresses: jeuribe@uniandes.edu.co (A. Uribe), heidi.mateus@urosario.edu.co (H.E. Mateus). 1 A. Uribe and H. E. Mateus contributed equally to this work. http://dx.doi.org/10.1016/j.gene.2015.08.018 0378-1119/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Gene journal homepage: www.elsevier.com/locate/gene