Genetic and Phenotypic Basis of Autosomal Dominant Parkinson's Disease in a Large Multi-Center Cohort.

, and are unequivocally associated with autosomal dominant Parkinson's disease (PD). We evaluated the prevalence of , and mutations and associated clinical features in a large French multi-center cohort of PD patients. Demographic and clinical data were collected for 1,805 index cases (592 with autosomal dominant inheritance and 1,213 isolated cases) since 1990.

FXTAS: new insights and the need for revised diagnostic criteria.

Objective: Fragile X-associated tremor ataxia syndrome (FXTAS) is defined by FMR1 premutation, cerebellar ataxia, intentional tremor, and middle cerebellar peduncle (MCP) hyperintensities. We delineate the clinical, neurophysiologic, and morphologic characteristics of FXTAS.

Methods: Clinical, morphologic (brain MRI, (123)I-ioflupane SPECT), and neurophysiologic (tremor recording, nerve conduction studies) study in 22 patients with FXTAS, including 4 women.

EIF4G1 in familial Parkinson's disease: pathogenic mutations or rare benign variants?

Mutations in the eukaryotic translation initiation factor 4-gamma (EIF4G1) gene, encoding a component of the eIF4F translation initiation complex, were recently reported as a possible cause for the autosomal dominant form of Parkinson's disease (PD). Here, we describe the screening of all 31 EIF4G1 coding exons in a series of 251 index cases with autosomal dominant PD, mostly of French origin and in 236 European control subjects. We identified 12 rare coding variants (either nonsynonymous amino acid substitutions or in frame deletions/insertions), including 6 variants present only in cases and 3 in controls.

REEP1 mutations in SPG31: frequency, mutational spectrum, and potential association with mitochondrial morpho-functional dysfunction.

Hereditary spastic paraplegias (HSP) constitute a heterogeneous group of neurodegenerative disorders characterized at least by slowly progressive spasticity of the lower limbs. Mutations in REEP1 were recently associated with a pure dominant HSP, SPG31. We sequenced all exons of REEP1 and searched for rearrangements by multiplex ligation-dependent probe amplification (MLPA) in a large panel of 175 unrelated HSP index patients from kindreds with dominant inheritance (AD-HSP), with either pure (n = 102) or complicated (n = 73) forms of the disease, after exclusion of other known HSP genes.

Parkinson's disease-related LRRK2 G2019S mutation results from independent mutational events in humans.

Mutations in the leucine-rich-repeat kinase 2 (LRRK2) gene have been identified in families with autosomal dominant Parkinson's disease (PD) and in sporadic cases; the G2019S mutation is the single most frequent. Intriguingly, the frequency of this mutation in PD patients varies greatly among ethnic groups and geographic origins: it is present at <0.1% in East Asia, approximately 2% in European-descent patients and can reach frequencies of up to 15-40% in PD Ashkenazi Jews and North African Arabs.

Follow-up study of the GIGYF2 gene in French families with Parkinson's disease.

Meeus et al. (2009) reported no pathogenic mutations in a comprehensive genetic analysis of the entire GRB10-interacting GYF protein-2 gene (GIGYF2) in a Belgian series of both familial and sporadic patients with Parkinson's disease (PD). Although we initially proposed that GIGYF2 corresponds to the PARK11 locus, in familial PD, we found no causative variations in a follow-up study in which GIGYF2 was screened in an independent series of 185 patients with autosomal dominant PD, mostly of French origin.

Mutations in SPG11, encoding spatacsin, are a major cause of spastic paraplegia with thin corpus callosum.

Autosomal recessive hereditary spastic paraplegia (ARHSP) with thin corpus callosum (TCC) is a common and clinically distinct form of familial spastic paraplegia that is linked to the SPG11 locus on chromosome 15 in most affected families. We analyzed 12 ARHSP-TCC families, refined the SPG11 candidate interval and identified ten mutations in a previously unidentified gene expressed ubiquitously in the nervous system but most prominently in the cerebellum, cerebral cortex, hippocampus and pineal gland. The mutations were either nonsense or insertions and deletions leading to a frameshift, suggesting a loss-of-function mechanism.