SPG3A mutations important cause of HSP

Posted - June 2007 in Research Highlights

Mutations in SPG3A represent an important cause in the overall HSP population. SPG3A is more often associated with a neuropathy than previously assumed. Therefore, patients with a bipyramidal syndrome and a neuropathy should be screened for mutations in SPG3A.

Objective

To study the frequency and distribution of mutations in SPG3A in a large cohort of patients with hereditary spastic paraplegia.

Design

We screened a large cohort of 182 families and isolated cases with pure or complex hereditary spastic paraplegia phenotypes, which were negative for mutations in SPG4.

Results

In 12 probands (6.6%), we identified 12 different SPG3A mutations (11 missense and 1 insertion/frameshift) of which 7 were novel and 3 were de novo. We found incomplete penetrance in 1 family (G482V). In most cases, SPG3A mutations were associated with an early age at onset (mean, 3 y); however, in 1 family (R495W mutation), symptoms started later (mean, 14 y) with clear intrafamilial variability (8-28 y). Six patients with an SPG3A mutation (F151S, Q191R, M408T, G469A, R495W) originating from 5 unrelated families presented with a complex form of hereditary spastic paraplegia associated with a neuropathy (17%). Our electrophysiological and pathological findings confirmed an axonal sensory-motor neuropathy. There was no correlation between the genotype and the presence of a neuropathy.

Conclusions

We conclude that mutations in SPG3A represent an important cause of patients in the overall hereditary spastic paraplegia population. SPG3A is more often associated with a neuropathy than previously assumed. Therefore, patients with a bipyramidal syndrome and a neuropathy should be screened for mutations in SPG3A.

Source

Arch Neurol. 2007 May;64(5):706-13.
Hereditary spastic paraplegia 3A associated with axonal neuropathy.
Ivanova N, Claeys KG, Deconinck T, Litvinenko I, Jordanova A, Auer-Grumbach M, Haberlova J, Löfgren A, Smeyers G, Nelis E, Mercelis R, Plecko B, Priller J, Zámecník J, Ceulemans B, Erichsen AK, Björck E, Nicholson G, Sereda MW, Seeman P, Kremensky I, Mitev V, De Jonghe P.
Laboratory of Molecular Pathology, Sofia Medical University, Sofia, Bulgaria.
PMID: 17502470 [PubMed – indexed for MEDLINE]