Expansion of the phenotypic spectrum of SPG6 caused by mutation in NIPA1.

BACKGROUND

Hereditary spastic paraplegia type 6 (SPG6) is caused by mutations in the NIPA1 gene, this is a rare cause of HSP, until now, all the affected individuals reported displayed "pure" spastic paraplegia.

OBJECTIVES

To analyze the genotype/phenotype correlation of mutations so far described in NIPA1.

METHODS

Eighty-six Chinese Han HSP patients were investigated for SPG6 mutations by direct sequencing of the NIPA1 gene.

RESULTS

One heterozygous missense mutation c.316G>C/p.G106R was identified in a complicated form of ADHSP family with peripheral nerves disease, and SPG6 mutation in our sample accounted for 3.6% (1/28) of ADHSP families and 1.1% (1/86) of non-ARHSP patients who were negative for SPG4, SPG3A and SPG31 mutations.

CONCLUSIONS

We report the first complicated case of SPG6 in the world by the presence of peripheral neuropathy, which extends the phenotype initially described.