Gaucher disease results, in most patients, from mutations in the gene encoding glucocerebrosidase. Mutation D409H is the third most frequent in Spanish patients, accounting for 5.7% of all mutated alleles. This allele is associated mainly with the neurological forms of the disease. Recently, homozygosity for the D409H mutation has been associated with a particular phenotype, including specific cardiovascular symptoms. Here we report a second Spanish patient bearing the D409H/D409H genotype with a very early manifestation of the disease. The patient started enzyme replacement therapy at 3 months of age. A common origin for the Spanish D409H alleles was ruled out by haplotype analysis using an internal polymorphism of the glucocerebrosidase gene and two external microsatellite markers.