Alteration of ganglioside biosynthesis responsible for complex hereditary spastic paraplegia.

Hereditary spastic paraplegias (HSPs) form a heterogeneous group of neurological disorders. A whole-genome linkage mapping effort was made with three HSP-affected families from Spain, Portugal, and Tunisia and it allowed us to reduce the SPG26 locus interval from 34 to 9 Mb. Subsequently, a targeted capture was made to sequence the entire exome of affected individuals from these three families, as well as from two additional autosomal-recessive HSP-affected families of German and Brazilian origins.

Deletion analysis of SMN and NAIP genes in Tunisian patients with spinal muscular atrophy.

Background: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder involving degeneration of anterior horn cells of spinal cord, resulting in progressive muscle weakness and atrophy.

Aims: The purpose of our study was to determine the frequency of SMN and NAIP deletions in Tunisian SMA patients.

Materials And Methods: Polymerase chain reaction (PCR) combined with restriction fragment length polymorphism (RFLP) was used to detect the deletion of exon 7 and exon 8 of SMN1 gene, as well as multiplex PCR for exon 5 and 13 of NAIP gene.

Loss of function of glucocerebrosidase GBA2 is responsible for motor neuron defects in hereditary spastic paraplegia.

Spastic paraplegia 46 refers to a locus mapped to chromosome 9 that accounts for a complicated autosomal-recessive form of hereditary spastic paraplegia (HSP). With next-generation sequencing in three independent families, we identified four different mutations in GBA2 (three truncating variants and one missense variant), which were found to cosegregate with the disease and were absent in controls. GBA2 encodes a microsomal nonlysosomal glucosylceramidase that catalyzes the conversion of glucosylceramide to free glucose and ceramide and the hydrolysis of bile acid 3-O-glucosides.

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.

A new locus (SPG46) maps to 9p21.2-q21.12 in a Tunisian family with a complicated autosomal recessive hereditary spastic paraplegia with mental impairment and thin corpus callosum.

Hereditary spastic paraplegia (HSP) with thin corpus callosum (TCC) and mental impairment is a frequent subtype of complicated HSP, often inherited as an autosomal recessive (AR) trait. It is clear from molecular genetic analyses that there are several underlying causes of this syndrome, with at least six genetic loci identified to date. However, SPG11 and SPG15 are the two major genes for this entity.

CYP7B1 mutations in pure and complex forms of hereditary spastic paraplegia type 5.

Thirty-four different loci for hereditary spastic paraplegias have been mapped, and 16 responsible genes have been identified. Autosomal recessive forms of spastic paraplegias usually have clinically complex phenotypes but the SPG5, SPG24 and SPG28 loci are considered to be associated with 'pure' forms of the disease. Very recently, five mutations in the CYP7B1 gene, encoding a cytochrome P450 oxysterol 7-alpha hydroxylase and expressed in brain and liver, have been found in SPG5 families.

Screening of ARHSP-TCC patients expands the spectrum of SPG11 mutations and includes a large scale gene deletion.

Autosomal recessive spastic paraplegia with thinning of corpus callosum (ARHSP-TCC) is a complex form of HSP initially described in Japan but subsequently reported to have a worldwide distribution with a particular high frequency in multiple families from the Mediterranean basin. We recently showed that ARHSP-TCC is commonly associated with mutations in SPG11/KIAA1840 on chromosome 15q. We have now screened a collection of new patients mainly originating from Italy and Brazil, in order to further ascertain the spectrum of mutations in SPG11, enlarge the ethnic origin of SPG11 patients, determine the relative frequency at the level of single Countries (i.

Complicated forms of autosomal dominant hereditary spastic paraplegia are frequent in SPG10.

Hereditary spastic paraplegias (HSP) constitute a heterogeneous group of neurodegenerative disorders characterized by slowly progressive spasticity of the lower extremities. Only a few different mutations in the SPG10 gene, KIF5A, have been described in pure dominant forms of the disease. We sequenced the motor domain of KIF5A in a large panel of 205 European HSP patients with either pure or complicated forms of the disease.

Identification of the SPG15 gene, encoding spastizin, as a frequent cause of complicated autosomal-recessive spastic paraplegia, including Kjellin syndrome.

Hereditary spastic paraplegias (HSPs) are genetically and phenotypically heterogeneous disorders. Both "uncomplicated" and "complicated" forms have been described with various modes of inheritance. Sixteen loci for autosomal-recessive "complicated" HSP have been mapped.

Hereditary spastic paraplegia with mental impairment and thin corpus callosum in Tunisia: SPG11, SPG15, and further genetic heterogeneity.

Objective: To perform a clinical and genetic study of Tunisian families with autosomal recessive (AR) hereditary spastic paraplegia with thin corpus callosum (HSP-TCC).

Design: Linkage studies and mutation screening.

Setting: Reference Center for Neurogenetics in South and Center Tunisia.

Spastic paraplegia 15: linkage and clinical description of three Tunisian families.

Hereditary spastic paraplegias (HSP) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by slowly progressive spasticity of the lower limbs. The locus designated spastic paraplegia 15 (SPG15), located in a 16-Mb interval on chromosome 14q, is associated with a rare autosomal recessive complicated form of HSP known as Kjellin's syndrome. In this study, we describe three additional families, of Tunisian origin, linked to the SPG15 locus, one of which had a significant multipoint LOD score of 3.

Mutations in SPG11 are frequent in autosomal recessive spastic paraplegia with thin corpus callosum, cognitive decline and lower motor neuron degeneration.

Hereditary spastic paraplegias (HSP) are neurodegenerative diseases mainly characterized by lower limb spasticity associated, in complicated forms, with additional neurological signs. We have analysed a large series of index patients (n = 76) with this condition, either from families with an autosomal recessive inheritance (n = 43) or isolated patients (n = 33), for mutations in the recently identified SPG11 gene. We found 22 truncating mutations, including the first four splice-site mutations, segregating in seven isolated cases and 13 families.