Pierpaola Fenoglio

SQSTM1 mutations in frontotemporal lobar degeneration and amyotrophic lateral sclerosis

Objective: There is increasing evidence that common genetic risk factors underlie frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). Recently, mutations in the sequestosome 1 (SQSTM1) gene, which encodes p62 protein, have been reported in patients with ALS. P62 is a multifunctional adapter protein mainly involved in selective autophagy, oxidative stress response, and cell signaling pathways. The purpose of our study was to evaluate the frequency of SQSTM1 mutations in a dataset of unrelated patients with FTLD or ALS, in comparison with healthy controls and patients with Paget disease of bone (PDB). Methods: Promoter region and all exons of SQSTM1 were sequenced in a large group of subjects, including patients with FTLD or ALS, healthy controls, and patients with PDB. The clinical characteristics of patients with FTLD or ALS with gene mutations were examined. Results: We identified 6 missense mutations in the coding region of SQSTM1 in patients with either FTLD or ALS, none of which were found in healthy controls or patients with PDB. In silico analysis suggested a pathogenetic role for these mutations. Furthermore, 7 novel noncoding SQSTM1 variants were found in patients with FTLD and patients with ALS, including 4 variations in the promoter region. Conclusions: SQSTM1 mutations are present in patients with FTLD and patients with ALS. Additional studies are warranted in order to better investigate the role of p62 in the pathogenesis of both FTLD and ALS.

SQSTM1 gene analysis and gene-environment interaction in Paget's disease of bone

Even though SQSTM1 gene mutations have been identified in a consistent number of patients, the etiology of Pagets disease of bone (PDB) remains in part unknown. In this study we analyzed SQSTM1 mutations in 533 of 608 consecutive PDB patients from several regions, including the high‐prevalence area of Campania (also characterized by increased severity of PDB, higher number of familial cases, and peculiar phenotypic characteristics as giant cell tumor). Eleven different mutations (Y383X, P387L, P392L, E396X, M401V, M404V, G411S, D423X, G425E, G425R, and A427D) were observed in 34 of 92 (37%) and 43 of 441 (10%) of familial and sporadic PDB patients, respectively. All five patients with giant cell tumor complicating familial PDB were negative for SQSTM1 mutations. An increased heterogeneity and a different distribution of mutations were observed in southern Italy (showing 9 of the 11 mutations) than in central and northern Italy. Genotype‐phenotype analysis showed only a modest reduction in age at diagnosis in patients with truncating versus missense mutations, whereas the number of affected skeletal sites did not differ significantly. Patients from Campania had the highest prevalence of animal contacts (i.e., working or living on a farm or pet ownership) without any difference between patients with or without mutation. However, when familial cases from Campania were considered, animal contacts were observed in 90% of families without mutations. Interestingly, a progressive age‐related decrease in the prevalence of animal contacts, as well as a parallel increase in the prevalence of SQSTM1 mutations, was observed in most regions except in the subgroup of patients from Campania. Moreover, patients reporting animal contacts showed an increased number of affected sites (2.54 ± 2.0 versus 2.19 ± 1.9, p < .05) over patients without animal contacts. This difference also was evidenced in the subgroup of patients with SQSTM1 mutations (3.84 ± 2.5 versus 2.76 ± 2.2, p < .05). Overall, these data suggest that animal‐related factors may be important in the etiology of PDB and may interact with SQSTM1 mutations in influencing disease severity.

Haplotype Analysis Confirms the Association Between the HCRTR2 Gene and Cluster Headache

Background.— Several studies suggested that genetic factors play a role in cluster headache (CH) susceptibility. We found a significant association between the 1246 G>A polymorphism of the hypocretin receptor‐2 (HCRTR2) gene and the disease. This association was confirmed in a large study from Germany but was not replicated in a dataset of CH patients from Northern Europe.

TUMOR NECROSIS FACTOR-α GENE AND CEREBRAL ANEURYSMS

OBJECTIVEThe pathogenesis of intracranial aneurysms is still uncertain. In addition to atherosclerosis, immunological factors may play a role in the disease. Recent studies have suggested that tumor necrosis factor-α (TNF-α), one of the main proinflammatory cytokines, may play a key role in the formation and rupture of cerebral aneurysms. The purpose of this study is to evaluate the association of a functionally active polymorphism (−308 G<A) in the TNF-α gene with the risk and the clinical features of aneurysmal subarachnoid hemorrhage. METHODSA total of 171 consecutive aneurysmal subarachnoid hemorrhage patients and 144 healthy controls were involved in the study. Computed tomographic scan findings were assessed by Fisher grade; clinical neurological assessment was performed using the Hunt and Hess grading system. Patients and controls were genotyped for the−308 biallelic (G<A) polymorphism of the TNF-α gene. RESULTSThe TNF-α G allele was significantly more frequent in patients than in controls (χ2 = 5.59; P = 0.0181) and homozygosity for the G allele, compared with remaining genotypes, was associated with a significantly increased risk of aneurysmal subarachnoid hemorrhage (odds ratio = 2.20; 95% confidence interval = 1.29<odds ratio<3.75). Allelic and genotypic frequencies of the examined polymorphism were not significantly different in disease subgroups. The different TNF-α genotypes do not seem to significantly modify the main clinical features of the disease. CONCLUSIONOur data suggests that the TNF-α gene or a linked locus significantly modulates the risk for aneurysmal subarachnoid hemorrhage. Additional studies in different populations are warranted to confirm our findings.

Association between Major Mood Disorders and the hypocretin receptor 1 gene

BACKGROUND Recent studies suggested a role for hypocretins in the neurobiology of Major Mood Disorders (MMD). The purpose of this study was to investigate hypocretin involvement in MMD evaluating whether particular alleles or genotypes of the hypocretin pathway genes (HCRT, HCRTR1 and HCRTR2) would modify the occurrence and clinical features of the disease. METHODS We selected for the study 229 MMD patients and 259 healthy age-, sex- and ethnicity-matched controls. Cases and controls were genotyped for several single-nucleotide polymorphisms (SNPs) of the HCRT, HCRTR1, and HCRTR2 genes. RESULTS We found that allelic and genotypic frequencies of the rs2271933 G>A polymorphism (Ile408Val) in the HCRTR1 gene were significantly different between cases and controls (p=0.003 and p=0.0004, respectively). The carriage of the A allele was associated with a significantly increased disease risk (OR:1.60, 95% C.I. 1.22-2.10). In addition, we found a significant association between HCRTR1 haplotypes and the disease (permutation p<0.0001). In the analysis of subgroups we confirmed the association only in patients with unipolar depression. LIMITATIONS Our sample was relatively small and included only cases and controls recruited from Northern Italy. Analysis of the disease subgroups warrants reexamination with more subjects. Finally, the effects of the rs2271933 G>A polymorphism on the hypocretin-1 receptor function are unknown. CONCLUSIONS Our study suggests that the HCRTR1 gene or a linked locus may modulate the risk for Major Mood Disorders and supports recent studies suggesting an involvement of hypocretin neurotransmitter system in affective disorders.

Cluster Headache is Associated With the Alcohol Dehydrogenase 4 (ADH4) Gene

(Headache 2010;50:92‐98)

Genetic variants in the NOTCH4 gene influence the clinical features of migraine

BackgroundRecent studies suggested an important role for vascular factors in migraine etiopathogenesis. Notch4 belongs to a family of transmembrane receptors that play an important role in vascular development and maintenance. The aim of this study was to test the hypothesis that polymorphisms of the NOTCH4 gene would modify the occurrence and the clinical features of migraine.FindingsUsing a case–control strategy, we genotyped 239 migraine patients and 264 controls for three different non-synonymous polymorphisms (T320A, G835V, R1346P) of the NOTCH4 gene and for the (CTG) n-encoding polyleucine polymorphism in exon 1. Although the analyzed polymorphisms resulted not associated with migraine, the clinical characteristics of our patients were significantly influenced by the different NOTCH4 genotypes. Longer duration of disease and severity of neurovegetative symptoms during headache attacks were associated with the R1346P and G835V polymorphisms, respectively. In female patients, worsening of migraine symptoms at menarche was significantly correlated with T320A polymorphism.ConclusionsOur study shows that genetic variations within the NOTCH4 gene significantly modify the clinical characteristics of migraine and may have a role in disease pathogenesis.

Interleukin-1 cluster gene polymorphisms and aneurysmal subarachnoid hemorrhage.

BACKGROUNDEmerging data indicate that proinflammatory cytokines may be involved in the pathogenesis of intracranial aneurysms. Interleukin (IL)-1 is a proinflammatory cytokine that plays a pivotal role in both acute and chronic central nervous system injuries. OBJECTIVETo investigate whether select polymorphisms in the IL-1α, IL-1β, and IL-1 receptor antagonist genes are associated with both susceptibility to and clinical characteristics of subarachnoid hemorrhage due to intracranial aneurysm rupture. METHODSAllelic and genotypic frequencies of the IL-1α (−889), IL-1β (-511), and IL-1 receptor antagonist (VNTR) genes were determined in 215 patients and 155 healthy controls. Patient files were reviewed for the clinical characteristics at hospital admission and at 6-month follow-up. RESULTSNo association between aneurysmal subarachnoid hemorrhage susceptibility and the examined cytokine gene polymorphisms was found. Haplotype analysis did not show any significant difference between cases and controls. However, aneurysmal subarachnoid hemorrhage patients carrying the T/T genotype of the IL-1β gene showed a significant (P = .034) increase in the Hunt and Hess scores at hospital admission and a significant (P = .026) reduction in 6-month Glasgow Outcome Scale scores. The remaining polymorphisms showed no effect on the clinical features examined. CONCLUSIONOur results do not support the hypothesis that genetic variation in select polymorphisms of the IL-1 cluster genes is associated with aneurysmal subarachnoid cerebral hemorrhage. However, the IL-1β gene may modify disease severity and may be regarded as disease severity gene.

Absence of TARDBP Gene Mutations in an Italian Series of Patients with Frontotemporal Lobar Degeneration

Background/Aim: Recent studies showed that TAR DNA-binding protein 43 (TDP-43), encoded by the TARDBP gene, is a major pathological protein in both sporadic and familial frontotemporal lobar degeneration (FTLD). The aim of this study was to search for mutations of the TARDBP gene in the disease. Methods: We sequenced the TARDBP gene in 172 unrelated FTLD patients recruited from 2 Italian memory clinics. Results: We identified 3 different variants of the TARDBP gene in 12 FTLD patients. Three patients showed a silent variant, Ala66Ala (c.332T → C) in exon 2. A novel heterozygous mutation was found in intron 4 (c.543 + 51A → G) in 1 patient, which is not located at the splicing site. Finally, a c.208C → T variant in the 3′ untranslated region was detected in 8 probands. None of the aforementioned variants were predicted to affect TDP-43. Hence, pathogenic mutations were not identified in any of the FTLD cases. Conclusion: Our study, in accord with previous studies in different populations, found no evidence for a major genetic role of the TARDBP gene in FTLD.

Haemochromatosis gene (HFE) polymorphisms and migraine: an association study

Several studies have suggested that iron metabolism may be involved in the pathogenesis of migraine. Using a case-control design, we performed an association study in a cohort of Italian migraine patients to evaluate whether a particular allele or genotype of the haemochromatosis gene (HFE) would modify the occurrence and clinical features of the disease. We genotyped 256 migraine patients and 237 healthy age-, sex- and ethnicity-matched controls for the C282Y and H63D polymorphisms of the HFE gene. Phenotype and allele frequencies of both polymorphisms were similarly distributed in migraine patients and controls. The patients carrying the DD genotype of the H63D polymorphism showed a later age at onset of the disease and an increased number of migraine attacks. Our data suggest that the HFE gene is not a major disease gene for migraine. However, the H63D polymorphism of the HFE gene may be considered a modifying genetic factor in migraine.