Neuropediatrics 2006; 37 - MP48
DOI: 10.1055/s-2006-943645

SPASTIC PARAPLEGIA WITH THIN CORPUS CALLOSUM AND MENTAL RETARDATION (SPG11): CLINICAL AND GENETIC STUDY IN 10 PATIENTS

F Kok 1, C Bueno 1, D Schlesinger 1, M Martyn 1, A Pessoa 1, M Zatz 1
  • 1Pediatric Neurology Service, University of Sao Paulo School of Medicine, Sao Paulo, SP, Brazil

Objectives: Hereditary spastic paraplegias (SPG) are a group of neurodegenerative disorders that can be inherited as an autosomal recessive, dominant or X-linked recessive trait. So far, up to 29 loci have been recognized, and 11 genes identified. SPG might be pure, when paraplegia is the only manifestation, or complicated, when it is accompanied by other symptoms, as dementia, peripheral neuropathy, retinitis pigmentosa and epilepsy. SPG11 is one of the 15 known recessive forms of spastic paraplegias and it is characterized by mental retardation and/or dementia and thin corpus callosum. In some families, SPG11 is linked to 15q13–15, but its gene was not identified. SPG 11 has been reported worldwide and might be one of the more common recessively inherited forms of SPG. The purpose of this presentation is to report clinical, MRI and genetic data on new observations on SPG11.

Methods: In the last two years, we evaluated 10 individuals, belonging to 7 families (3 of then consanguineous and 2 with more than one affected sibling) with SPG11. MRI was performed in at least one of the affected individual in each family. In consanguineous or with multiple affected siblings families, a genetic analysis using polymorphic markers for 15q13–15 was performed. Results: Clinical phenotype was quite similar and includes: 1. Onset in the 1st or 2nd decades of life, with mental retardation or dementia; 2. Spastic paraplegia with onset at 2nd decade; 3. Clinical signs, as cerebellar ataxia, peripheral neuropathy, epilepsy were variably present; 4. Brain MRI showed thin corpus callosum in all studied patients. In pedigrees with multiple affected individuals, they share the same haplotype for 15q13–15; in consanguineous families, affected individuals are homozygous for this same region.

Conclusion: Spastic paraplegia with thin corpus callosum is a distinct phenotype that might be investigated in complicated SPG with recessive inheritance.