Report of the Spanish Gaucher's disease registry: clinical and genetic characteristics.

BACKGROUND AND OBJECTIVES: Since 1993 the demographic, clinical, analytical, genetic and follow-up data of Spanish patients with Gaucher's disease (GD) have been collected in an anonymous national database. Some statistical analyses of these data are reported concerning the distribution, clinical and genetic characteristics of GD in Spain and the response to enzyme replacement therapy (ERT) is evaluated. DESIGN AND METHODS: We performed a cohort study in Spanish GD patients by national inquiry, submitted by mail to 75 Spanish hospitals (over 300 beds) directed to internal medicine, hematology and pediatric departments. The questionnaire included 30 questions (gender, height, weight, date of birth, date of diagnosis, abode and number of relatives affected, bone crises, neurologic symptoms, other symptoms, liver and spleen size, hemoglobin, leukocyte and platelet count, tartrate resistant acid phosphatase, ALT/AST, chitotrioxidase activity, total plasma cholesterol, triglycerides, high density lipoprotein cholesterol, enzymatic activity of acid -glycosides, mutation, X-ray examination, magnetic resonance imaging-MRI-evaluation, spleen removal, and orthopedic procedures (ERT, date of first infusion). Each case with a presumed diagnosis was considered an enrolled patient. Written informed consent was obtained from all patients. The cases without enzymatic or genetic diagnosis were studied in a reference laboratory (the same for all the samples). Clinical status was evaluated by Zimran's severity score index. The enzymatic activity of acid -glycosides was determined in cellular extracts of peripheral blood granulocytes by a fluorescent method using an artificial substrate (4-methyl-umbelliferyl -D-glycoside). Polymerase chain reaction (PCR) molecular analysis was performed in DNA samples to characterize the mutations (N370S, L444P, IVS2+1, 84GG, D409H, R463C and G377S) of the glycoside genes. Two groups were created according to age at diagnosis: children under 15 years and adults, in order to evaluate clinical, genetics and follow-up. Effectiveness of ERT was evaluated using objective parameters (hemoglobin, platelets, liver and spleen size, skeletal lesions), before and after therapy. In patients under ERT, quality of life (QOL) was assessed by a SF-36 modified inquiry, including 22 questions. Statistical analysis including descriptive and frequency distribution for each variable was performed, the ANOVA test was used to identify differences between groups. Paired t-tests (before and during therapy) were carried out. The degree of linear association among measured variables was estimated by Pearson's correlation.
RESULTS: By December 1999 one hundred and fifty-five patients from 117 families had been included from 66 Spanish Hospitals; the inquiry was complete for 114 patients. Mean age at diagnosis: 24.0+/-16.9 years, M/F: 72/83. No symptoms were present at diagnosis in 19.3%; visceral disease was present in 95.6% and bone disease in 62.4%. Hemoglobin levels, leukocyte and platelet counts were below the normal range in 62.3% of cases. Higher acid phosphatase levels were observed in 99% of cases; biochemical liver dysfunction tests were found in 42.9%. The test for acid glycosidase showed a marked decrease in enzymatic activity. Morphologic documentation (spleen or liver tissue, bone marrow biopsy or aspirate) of GD was obtained in 71% of the patients. The most frequent mutations observed were N370S (46.3% of the alleles detected), and L444P (18.5%). In 18.7% of the cases the disease was stable or progressing slightly; in 23.8% the spleen had been removed between 1-14 years after diagnosis and 60.6% were under ERT. Children showed both greater liver enlargement and higher SSI (p = 0.0001). There was a correlation between SSI and clinical or analytical data in adults patients for spleen size (Z: 3.142; CI: 0. 173-0.637; p= 0.0017). In 35 patients on ERT, clinical and analytic data improved as did self-evaluated QOL (p< 0.0001). (A