Two children, brother and sister, were diagnosed with type 1 Gaucher disease (GD) at the ages of 2 and 1 year, respectively. The oldest child was hospitalised for severe thrombopenia related to an Epstein–Barr virus infection. A myelogram was performed, due to large splenomegaly, Gaucher cells were observed. The diagnosis of GD for both was confirmed by a very low level of glucocerebrosidase activity.
The younger sister had splenomegaly and thrombopenia (120 000/mm3). The two children were compound heterozygotes for two missense mutations: pR48W (c259C>T) and pG193R (c694G>A), a novel mutation. After an observation period of 3 years, enzyme replacement therapy (ERT) with imiglucerase (Cerezyme, Genzyme) was started for both patients, at the dose of 60 U/kg per 2 weeks due to a large splenomegaly and platelet count below 50 000/mm3. The platelet count increased to 150 000/mm3 after 6 months and 200 000/mm3 after one year of treatment, splenomegaly disappeared. Size and weight growth curves returned to normal. After 7 years of treatment no bone disease nor late side effect was noticed. Cerezyme was progressively reduced to 30 U/kg per 2 weeks with no effect on haematological parameters, but a significant increase in chitotriosidase led to a resumption of the initial dose. These cases emphasise: (1) the benefit of an early diagnosis and early ERT initiation in strong phenotype expression GD children; (2) the short-term beneficial effect of ERT on haematological, organic and somatic, social involvements; (3) the need to maintain ERT dosing of 60 U/kg per 2 weeks until puberty in order to ensure a normal growth and normal bone maturation, hence avoiding debilitating bone sequels in the long term.