Hereditary Spastic Paraplegias (HSP) are characterized by progressive spasticity and weakness of the lower limbs. At least 45 loci have been identified in families with autosomal dominant (AD), ...autosomal recessive (AR), or X-linked hereditary patterns. Mutations in the SPAST (SPG4) and ATL1 (SPG3A) genes would account for about 50% of the ADHSP cases.
We defined the SPAST and ATL1 mutational spectrum in a total of 370 unrelated HSP index cases from Spain (83% with a pure phenotype).
We found 50 SPAST mutations (including two large deletions) in 54 patients and 7 ATL1 mutations in 11 patients. A total of 33 of the SPAST and 3 of the ATL1 were new mutations. A total of 141 (31%) were familial cases, and we found a higher frequency of mutation carriers among these compared to apparently sporadic cases (38% vs. 5%). Five of the SPAST mutations were predicted to affect the pre-mRNA splicing, and in 4 of them we demonstrated this effect at the cDNA level. In addition to large deletions, splicing, frameshifting, and missense mutations, we also found a nucleotide change in the stop codon that would result in a larger ORF.
In a large cohort of Spanish patients with spastic paraplegia, SPAST and ATL1 mutations were found in 15% of the cases. These mutations were more frequent in familial cases (compared to sporadic), and were associated with heterogeneous clinical manifestations.
Abstract A recent genome-wide association study (GWA) reported a significant association between single nucleotide polymorphisms (SNPs) at the PCDH11X gene and late-onset Alzheimer's disease (LOAD). ...Our research was designated to replicate this association, including non previously analyzed PCDH11X and PCDH11Y SNPs. We genotyped four PCDH11X and one PCDH11Y SNPs in a total of 420 LOAD patients and 350 healthy controls from Spain. Allele and genotype frequencies did not differ between patients and controls for the five SNPs, even after correcting by gender, age, and APOE-ε4 status. Our data were in agreement with recent reports that failed to confirm the association between PCDH11X polymorphisms and LOAD, and extended the lack of association to common PCDH11Y variants.
MYH7 mutations are found in ∼20% of hypertrophic cardiomyopathy (HCM) patients. Currently, mutational analysis is based on the sequencing of the coding exons and a few exon-flanking intronic ...nucleotides, resulting in omission of single-exon deletions and mutations in internal intronic, promoter, and 3′ UTR regions. We amplified and sequenced large MYH7 fragments in 60 HCM patients without previously identified sarcomere mutations. Lack of aberrant PCR fragments excluded single-exon deletions in the patients. Instead, we identified several new rare intronic variants. An intron 26 single nucleotide insertion (−5 insC) was predicted to affect pre-mRNA splicing, but allele frequencies did not differ between patients and controls ( n = 150). We found several rare promoter variants in the patients compared to controls, some of which were in binding sites for transcription factors and could thus affect gene expression. Only one rare 3′ UTR variant (c.*29T>C) found in the patients was absent among the controls. This nucleotide change would not affect the binding of known microRNAs. Therefore, MYH7 mutations outside the coding exon sequences would be rarely found among HCM patients. However, changes in the promoter region could be linked to the risk of developing HCM. Further research to define the functional effect of these variants on gene expression is necessary to confirm the role of the MYH7 promoter in cardiac hypertrophy.
DNA variation at the
FGF20 gene has been associated with Parkinson's disease (PD). In particular, SNP rs12720208 in the 3′ untranslated region (3′ UTR) was linked to PD-risk through a mechanism that ...would implicate a differential binding to microRNA-433 (miR-433). The reduction of the affinity of miR-433 to the 3′ UTR would result in increased
FGF20 expression and upregulation of alpha-synuclein, which could in turn promote dopaminergic neurons degeneration. We genotyped the rs12720208 SNP in a total of 512 PD patients and 258 healthy controls from Spain, and searched for miR-433 variants in the patients. We did not find significant differences in allele and genotype frequencies between patients and controls. None of the patients had miR-433 variants. In conclusion, our work did not confirm the association between rs12720208 and PD, or an effect of miR-433 variants on this disease.
Alpha-synuclein gene (
SNCA
) polymorphisms have been associated with the common sporadic form of Parkinson’s disease (PD). We searched for DNA variants at the
SNCA
3′ UTR through single strand ...conformation analysis and direct sequencing in a cohort of Spanish PD patients and controls. We have genotyped the rs356165
SNCA
3′ UTR polymorphism in a total of 1,135 PD patients and 772 healthy controls from two Spanish cohorts (Asturias and Navarre). We identified six
SNCA
3′ UTR variants. Single nucleotide polymorphism (SNP) rs356165 was significantly associated with PD risk in the Spanish cohort (
p
= 0.0001; odd ratio = 1.37, 95%CI = 1.19–1.58). This SNP was also significantly associated with early age at onset of PD. Our work highlights rs356165 as an important determinant of the risk of developing PD and early age at onset and encourages future research to identify a functional effect on
SNCA
expression.
Angiotensin and serotonin have been identified as inducers of cardiac hypertrophy. DNA polymorphisms at the genes encoding components of the angiotensin and serotonin systems have been associated ...with the risk of developing cardiovascular diseases, including left ventricular hypertrophy (LVH).
We genotyped five polymorphisms of the AGT, ACE, AT1R, 5-HT2A, and 5-HTT genes in 245 patients with Hypertrophic Cardiomyopathy (HCM; 205 without an identified sarcomeric gene mutation), in 145 patients with LVH secondary to hypertension, and 300 healthy controls.
We found a significantly higher frequency of AT1R 1166 C carriers (CC+AC) among the HCM patients without sarcomeric mutations compared to controls (p = 0.015; OR = 1.56; 95%CI = 1.09-2.23). The AT1R 1166 C was also more frequent among patients who had at least one affected relative, compared to sporadic cases. This allele was also associated with higher left ventricular wall thickness in both, HCM patients with and without sarcomeric mutations.
The 1166 C AT1R allele could be a risk factor for cardiac hypertrophy in patients without sarcomeric mutations. Other variants at the AGT, ACE, 5-HT2A and 5-HTT did not contribute to the risk of cardiac hypertrophy.
► IL12B SNP rs6887695 was strongly associated with psoriasis. ► Sequencing of IL12B in psoriasis patients identified several known polymorphisms. ► None of the five additional SNPs was a risk factor ...for psoriasis.
Recent genomic surveys have identified IL12B as susceptibility locus for psoriasis (Ps). Our aim was to replicate the association between IL12B SNPs and Ps. In addition, we sequenced the IL12B gene in several patients to identify new variants that could explain the disease-risk.
A total of 304 Ps-patients and 422 healthy controls (all Caucasian Spanish) were genotyped for three IL12B polymorphisms. SNP rs6887695 (GG genotype) was significantly associated with Ps (p=0.002; OR=1.60, 95% CI=1.19–2.16). This genotype was also more frequent among patients with severe psoriasis (p=0.03). Sequencing of 30 patients with the risk genotype identified several IL12B reported SNPs. Allele and genotype frequencies for two putative functional variants (rs3213120 and rs3213119) did not differ between patients and controls.
Our study confirmed rs6887695 as a risk factor for Ps. No other IL12B variants that could explain this association were found in our patients.
Mitochondrial dysfunction could contribute to the development of spastic paraplegia. Among others, two of the genes implicated in hereditary spastic paraplegia encoded mitochondrial proteins and some ...of the clinical features frequently found in these patients resemble those observed in patients with mitochondrial DNA (mtDNA) mutations. We investigated the association between common mtDNA polymorphisms and spastic paraplegia. The ten mtDNA polymorphisms that defined the common European haplogroups were determined in 424 patients, 19% with a complicated phenotype. A rare haplogroup was associated with the disease in patients without a
SPG3A
,
SPG4
, or
SPG7
mutation. Allele 10398G was more frequent among patients with a pure versus complicated phenotype. This mtDNA polymorphism was previously associated with the risk of developing other neurodegenerative diseases. In conclusion, some mtDNA polymorphisms could contribute to the development of spastic paraplegia or act as modifiers of the phenotype.
Abstract
Background: The Vaqueiros de Alzada are a human isolate from Asturias, a Northern Spain region. Several hypotheses have been proposed to explain the origin of Vaqueiros.
Methods and results: ...To determine whether the Vaqueiros and non-Vaqueiros from the same region have different genetic backgrounds, this study analysed nine mtDNA polymorphisms that define the common European mitochondrial haplogroups in a cohort of Vaqueiros (n = 60) and non-Vaqueiros (n = 110). Haplogroup H was the most frequent in Vaqueiros (42%) and non-Vaqueiros (46%). A total of 37% Vaqueiros were H1, compared to 31% of the non-Vaqueiros. This study also genotyped the two groups for three polymorphisms at the NOS3. APOE and ACE genes, that have previously been linked to risk of cardiovascular diseases. Allele and genotype frequencies did not differ between Vaqueiros and non-Vaqueiros. In addition, none of these polymorphisms were related to risk of hypertension, diabetes or hypercholesterolaemia in the two groups.
Conclusion: The data suggested that Vaqueiros share the main haplogroup distribution as their non-Vaqueiros neighbours and other Cantabrian populations. In addition, no effect of the mitochondrial, NOS3. APOE and ACE polymorphisms on cardiovascular risk factors was observed.
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