[Japan spastic paraplegia research consortium (JASPAC)]

Area of Science:

• Neurogenetics
• Human Genetics
• Neurology

Context:

• Hereditary spastic paraplegia (HSP) is a group of inherited neurological disorders.
• The Japan Spastic Paraplegia Research Consortium (JASPAC) initiated a nationwide survey in 2006 to investigate HSP in Japan.
• As of October 2010, 321 index patients from 40 prefectures were registered.

Purpose:

• To conduct molecular testing on HSP patients using various genetic analysis techniques.
• To identify the genetic basis of HSP in the Japanese population.
• To improve diagnosis, follow-up, and genetic counseling for HSP patients.

Summary:

• SPG4 was identified as the most frequent cause of autosomal dominant HSP (ADHSP) in 144 Japanese families, accounting for 47% of cases.
• Other identified forms include SPG31 (4%), SPG3A (3%), SPG8 (1%), and SPG10 (1%).
• SPG11 and ARSACs appear common in autosomal recessive HSP (ARHSP) families, while approximately 40% of ADHSP cases remain genetically undefined.

Impact:

• Molecular testing results will enhance diagnostic accuracy and inform patient management and genetic counseling.
• High-throughput linkage analysis will be employed to identify novel disease-associated genes for undiagnosed HSP.
• JASPAC aims to comprehensively understand HSP phenotypes, including clinical features, mutations, genotype-phenotype correlations, and pathophysiology.