Hereditary spastic paraplegias: an update.
OBJECTIVE
Hereditary spastic paraplegias are a genetically heterogeneous group of diseases. Recent advances concerning their nosology and molecular bases have greatly improved the genetic diagnosis of these diseases, with implications for genetic counselling. The recent identification of new genes and loci, however, has blurred the distinction between hereditary spastic paraplegias and other entities, such as cerebellar ataxias or leucodystrophies. Cerebral MRI and the familial history of each patient with spastic paraplegia are the minimal clinical elements needed to orient genetic testing.


RESULTS
For SPG4, the gene most frequently involved in hereditary spastic paraplegias, a novel mutational mechanism was described, which allows detection of an increased number of cases. In autosomal recessive forms, mutations in the recently identified SPG11 gene seem to account for a majority of the complex forms of the disease with atrophy of the corpus callosum. In addition, the SACS gene has been implicated in an increasing number of cases of various origins.


CONCLUSIONS
Genetic testing is progressively more complex and clinical and other information concerning the phenotype is now crucial for choosing an appropriate genetic testing procedure for each patient.
Depienne
Christel
C
INSERM, U679, Paris, France.
Stevanin
Giovanni
G
Brice
Alexis
A
Durr
Alexandra
A
D000251:Adenosine Triphosphatases / Q000235:genetics; D004252:DNA Mutational Analysis / Q000379:methods; D003937:Diagnosis, Differential; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D040582:Inheritance Patterns / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D015419:Spastic Paraplegia, Hereditary / Q000175:diagnosis* / Q000235:genetics* / Q000503:physiopathology; D000074181:Spastin
D011506:Proteins; C520412:SPG11 protein, human; D000251:Adenosine Triphosphatases; D000074181:Spastin; C400283:SPAST protein, human