High proportion of mannosidosis and fucosidosis among lysosomal storage diseases in Cuba.

Although lysosomal storage disorders (LSDs) are considered individually rare, as a group they present a non-negligible frequency. Few studies have been made of populational occurrence of LSDs; they have been conducted predominantly on Caucasian populations. We studied the occurrence of LSDs in Cuba. Data from individuals who had been referred to the Institute of Neurology and Neurosurgery in Havana from hospitals all over the country between January 1990 and December 2005 were analyzed. This institute was the only laboratory to provide enzyme-based diagnostic testing for 19 LSDs in Cuba during this period. Occurrence rates were calculated by dividing the number of postnatal diagnoses by the number of births during the study period. The combined occurrence of LSDs in Cuba was 5.6 per 100,000, lower than that reported in other studies conducted on Caucasian populations. The most frequent individual LSDs were: mucopolysaccharidosis type I (1.01 per 100,000) and, surprisingly, alpha-mannosidosis (0.72 per 100,000) and fucosidosis (0.62 per 100,000). These findings may be related to specific genetic characteristics and admixture of the Cuban population. This is the first comprehensive study of the occurrence of LSDs in Cuba. We conclude that the epidemiology of these diseases can vary regionally, and we stress the need for similar surveys in other Latin American countries.

Phenotypic spectrum of fucosidosis in Tunisia.

Fucosidosis (OMIM 230000) is a rare autosomal recessive lysosomal disorder due to deficient α-L-fucosidase activity(EC 3.2.1.51), leading to the accumulation of fucose-containing glycolipids and glycoproteins in various tissues. This study contained the largest ever Tunisian survey of fucosidosis patients, diagnosed during the period 1987-2007. The clinical pictures and outcomes of these patients are compared with literature data. Ten patients (8 boys and 2 girls) from six unrelated families were diagnosed at a mean age of 29 ± 10.3 months. Six of the patients were diagnosed as having the more severe phenotype. The other four cases presented the low progressive phenotype. This distinction was determined by the presence or absence of angiokeratoma and age of death. For all of the patients in our survey, early motor development was more severely delayed than described in the literature. Six patients presented psychomotor decline during the second year of life. Clinical features consist of variable mental retardation (all patients), progressive spastic quadriplegia (6/10 cases), coarse facies (9/10 cases), growth retardation (7/9 cases), visceromegaly (3 cases), angiokeratoma corporis diffusum (4 cases), recurrent bronchopneumonias (all cases), seizures (4 cases) and variable degrees of dysostosis multiplex (all cases). Portal cavernoma, never described in the literature, was observed in one patient. The outcomes were severe in this survey, probably owing to restricted health care; death occurred in 6 of the 10 patients before age 10 years, following recurrent pulmonary infections and neurological deterioration. No intrafamilial variability was noted in the multiplex families. The clinical presentation and outcomes of some of these patients were consistent with the continuous clinical spectrum of severity in fucosidosis attested by most clinical studies.

Mutations in fucosidosis gene: a review.

Fucosidosis is an autosomal recessive disorder caused by a deficiency of alpha-L-fucosidase. Up to now 79 cases have been described and several others identified but not yet published. The higher incidence of the disease is in Italy, where nearly 20 patients have been identified. Fourteen disease-causing mutations have been detected and four of them, Q422X, G60D, E375X, P141fs are present in more than 70% of the forty patients studied. In Italian patients, only seven mutations have been described and P141fs and G60D mutations are present in more than 50% of the cases. The P141fs mutation is absent in other ethnic groups. It has been impossible to establish genotype-phenotype correlation so far and the clinical variability of the disease cannot be explained only by genetic heterogeneity.

Fucosidosis revisited: a review of 77 patients.

Fucosidosis is a rare, autosomal recessive, lysosomal storage disorder caused by a severe deficiency of alpha-L-fucosidase in all tissues. We have conducted a review of fucosidosis, compiling data from published reports and an international questionnaire survey. Seventy-seven patients affected with fucosidosis of which 19 had not been reported before have been identified. A major aim of the present study was to define the natural history of fucosidosis. The clinical picture of fucosidosis consists of progressive mental (95%) and motor (87%) deterioration, coarse facies (79%), growth retardation (78%), recurrent infections (78%), dysostosis multiplex (58%), angiokeratoma corporis diffusum (52%), visceromegaly (44%), and seizures (38%). Whereas the original fucosidosis patients described by Durand et al. (J. Pediatr 75:665-674, 1969) were decerebrate and died before age 5 years, most fucosidosis patients have a slower course of degeneration. Mortality before age 5 years was observed in only 7 patients (9%), whereas 36 patients (64%) reached the second decade. We did not find evidence for the existence of clinical heterogeneity with a rapidly progressive type I and a slowly progressive type II fucosidosis as suggested in the literature. Instead, there seems to exist a wide continuous clinical spectrum. At the biochemical level no heterogeneity in residual fucosidase enzyme activity or cross-reacting immunoreactive fucosidase protein was observed. At the DNA level at least 4 different mutations must be responsible for fucosidosis. These genotypic differences however do not explain the observed phenotypic differences.