Introduction: Lesch-Nyhan síndrome (LNS) is an X-linked recessive inborn error of metabolism, due to deficiency of the enzyme Hypoxanthine-guanine-phosphoribosyl transferase (HGPRT; EC.2.4.2.8) resulting in hyperuricemia, neurological and behavioural disturbances. In the present work, we report the results of the study of a Colombian family, where LNS was previously clinically and biochemically diagnosed. Material and Methods: The full HPRT gene, including 9 exons and 8 introns, was amplified on eight separate DNA fragments. Both strands, forward and reverse, of the amplified DNA fragments were analyzed and the obtained sequences were compared with those deposited at National Center for Biotechnology Information. Results and conclusions: Sequence analysis allowed the detection of new LNS causing mutation, an adenine deletion in exon 2 of HPRT1 gene resulting in a frameshift which determines a premature stop codon. This study, besides adding a new mutation to the already large spectrum of disease causing variation at HPRT, allows therefore providing genetic counseling for the family as well as prenatal diagnosis.