Spinocerebellar Ataxias: Phenotypic Spectrum of PolyQ versus Non-Repeat Expansion Forms.

Spinocerebellar ataxias (SCA) are most frequently due to (CAG)n (coding for polyglutamine, polyQ) expansions and, less so, to expansion of other oligonucleotide repeats (non-polyQ) or other type of variants (non-repeat expansion SCA). In this study we compared polyQ and non-repeat expansion SCA, in a cohort of patients with hereditary ataxia followed at a tertiary hospital. From a prospective study, 88 patients (51 families) with SCA were selected, 74 (40 families) of whom genetically diagnosed. Thirty-eight patients (51.4%, 19 families) were confirmed as having a polyQ (no other repeat-expansions were identified) and 36 (48.6%, 21 families) a non-repeat expansion SCA. Median age-at-onset was 39.5 [30.0-45.5] for polyQ and 7.0 years [1.00-21.50] for non-repeat expansion SCA. PolyQ SCA were associated with cerebellar onset, and non-repeat expansion forms with non-cerebellar onset. Time to diagnosis was longer for non-repeat expansion SCA. The most common polyQ SCA were Machado-Joseph disease (MJD/SCA3) (73.7%) and SCA2 (15.8%); whereas in non-repeat expansion SCA ATX-CACNA1A (14.3%), ATP1A3-related ataxia, ATX-ITPR1, ATX/HSP-KCNA2, and ATX-PRKCG (9.5% each) predominated. Disease duration (up to inclusion) was significantly higher in non-repeat expansion SCA, but the difference in SARA score was not statistically significant. Cerebellar peduncles and pons atrophy were more common in polyQ ataxias, as was axonal neuropathy. SCA had a wide range of genetic etiology, age-at-onset and presentation. Proportion of polyQ and non-repeat expansion SCA was similar; the latter had a higher genetic heterogeneity. While polyQ ataxias were typically linked to cerebellar onset in adulthood, non-repeat expansion forms associated with early onset and non-cerebellar presentations.

Genotype-first approach to identify associations between CDH1 germline variants and cancer phenotypes: a multicentre study by the European Reference Network on Genetic Tumour Risk Syndromes.

BACKGROUND: Truncating pathogenic or likely pathogenic variants of CDH1 cause hereditary diffuse gastric cancer (HDGC), a tumour risk syndrome that predisposes carrier individuals to diffuse gastric and lobular breast cancer. Rare CDH1 missense variants are often classified as variants of unknown significance. We conducted a genotype-phenotype analysis in families carrying rare CDH1 variants, comparing cancer spectrum in carriers of pathogenic or likely pathogenic variants (PV/LPV; analysed jointly) or missense variants of unknown significance, assessing the frequency of families with lobular breast cancer among PV/LPV carrier families, and testing the performance of lobular breast cancer-expanded criteria for CDH1 testing. METHODS: This genotype-first study used retrospective diagnostic and clinical data from 854 carriers of 398 rare CDH1 variants and 1021 relatives, irrespective of HDGC clinical criteria, from 29 institutions in ten member-countries of the European Reference Network on Tumour Risk Syndromes (ERN GENTURIS). Data were collected from Oct 1, 2018, to Sept 20, 2022. Variants were classified by molecular type and clinical actionability with the American College of Medical Genetics and Association for Molecular Pathology CDH1 guidelines (version 2). Families were categorised by whether they fulfilled the 2015 and 2020 HDGC clinical criteria. Genotype-phenotype associations were analysed by Student's t test, Kruskal-Wallis, χ2, and multivariable logistic regression models. Performance of HDGC clinical criteria sets were assessed with an equivalence test and Youden index, and the areas under the receiver operating characteristic curves were compared by Z test. FINDINGS: From 1971 phenotypes (contributed by 854 probands and 1021 relatives aged 1-93 years), 460 had gastric and breast cancer histology available. CDH1 truncating PV/LPVs occurred in 176 (21%) of 854 families and missense variants of unknown significance in 169 (20%) families. Multivariable logistic regression comparing phenotypes occurring in families carrying PV/LPVs or missense variants of unknown significance showed that lobular breast cancer had the greatest positive association with the presence of PV/LPVs (odds ratio 12·39 [95% CI 2·66-57·74], p=0·0014), followed by diffuse gastric cancer (8·00 [2·18-29·39], p=0·0017) and gastric cancer (7·81 [2·03-29·96], p=0·0027). 136 (77%) of 176 families carrying PV/LPVs fulfilled the 2015 HDGC criteria. Of the remaining 40 (23%) families, who did not fulfil the 2015 criteria, 11 fulfilled the 2020 HDGC criteria, and 18 had lobular breast cancer only or lobular breast cancer and gastric cancer, but did not meet the 2020 criteria. No specific CDH1 variant was found to predispose individuals specifically to lobular breast cancer, although 12 (7%) of 176 PV/LPV carrier families had lobular breast cancer only. Addition of three new lobular breast cancer-centred criteria improved testing sensitivity while retaining high specificity. The probability of finding CDH1 PV/LPVs in patients fulfilling the lobular breast cancer-expanded criteria, compared with the 2020 criteria, increased significantly (AUC 0·92 vs 0·88; Z score 3·54; p=0·0004). INTERPRETATION: CDH1 PV/LPVs were positively associated with HDGC-related phenotypes (lobular breast cancer, diffuse gastric cancer, and gastric cancer), and no evidence for a positive association with these phenotypes was found for CDH1 missense variants of unknown significance. CDH1 PV/LPVs occurred often in families with lobular breast cancer who did not fulfil the 2020 HDGC criteria, supporting the expansion of lobular breast cancer-centred criteria. FUNDING: European Reference Network on Genetic Tumour Risk Syndromes, European Regional Development Fund, Fundação para a Ciência e a Tecnologia (Portugal), Cancer Research UK, and European Union's Horizon 2020 research and innovation programme.

Functional characterization of a novel PRRT2 variant found in a Portuguese patient with hemiplegic migraine.

Familial hemiplegic migraine (FHM) is a rare autosomal-dominant form of migraine with aura. Three disease-causing genes have been identified for FHM: CACNA1A, ATP1A2 and SCN1A. However, not all families are linked to one of these three genes.PRRT2 variants were also commonly associated with HM symptoms; therefore, PRRT2 is hypothesized as the fourth gene causing FHM. PRRT2 plays an important role in neuronal migration, spinogenesis, and synapse mechanisms during development and calcium-dependent neurotransmitter release. We performed exome sequencing to unravel the genetic cause of migraine in one family, and a novel PRRT2 variant (c.938C > T;p.Ala313Val) was identified with further functional studies to confirm its pathogenicity. PRRT2-A313V reduced protein stability, led to protein premature degradation by the proteasome and altered the subcellular localization of PRRT2 from the plasma membrane (PM) to the cytoplasm. We identified and characterized for the first time in a Portuguese patient, a novel heterozygous missense variant in PRRT2 associated with HM symptoms. We suggest that PRRT2 should be included in the diagnosis of HM.

Iron Limitation Restores Autophagy and Increases Lifespan in the Yeast Model of Niemann-Pick Type C1.

Niemann-Pick type C1 (NPC1) is an endolysosomal transmembrane protein involved in the export of cholesterol and sphingolipids to other cellular compartments such as the endoplasmic reticulum and plasma membrane. NPC1 loss of function is the major cause of NPC disease, a rare lysosomal storage disorder characterized by an abnormal accumulation of lipids in the late endosomal/lysosomal network, mitochondrial dysfunction, and impaired autophagy. NPC phenotypes are conserved in yeast lacking Ncr1, an orthologue of human NPC1, leading to premature aging. Herein, we performed a phosphoproteomic analysis to investigate the effect of Ncr1 loss on cellular functions mediated by the yeast lysosome-like vacuoles. Our results revealed changes in vacuolar membrane proteins that are associated mostly with vesicle biology (fusion, transport, organization), autophagy, and ion homeostasis, including iron, manganese, and calcium. Consistently, the cytoplasm to vacuole targeting (Cvt) pathway was increased in ncr1∆ cells and autophagy was compromised despite TORC1 inhibition. Moreover, ncr1∆ cells exhibited iron overload mediated by the low-iron sensing transcription factor Aft1. Iron deprivation restored the autophagic flux of ncr1∆ cells and increased its chronological lifespan and oxidative stress resistance. These results implicate iron overload on autophagy impairment, oxidative stress sensitivity, and cell death in the yeast model of NPC1.

Non-coding variants in VAMP2 and SNAP25 affect gene expression: potential implications in migraine susceptibility.

Migraine is a common and complex neurological disease potentially caused by a polygenic interaction of multiple gene variants. Many genes associated with migraine are involved in pathways controlling the synaptic function and neurotransmitters release. However, the molecular mechanisms underpinning migraine need to be further explored.Recent studies raised the possibility that migraine may arise from the effect of regulatory non-coding variants. In this study, we explored the effect of candidate non-coding variants potentially associated with migraine and predicted to lie within regulatory elements: VAMP2_rs1150, SNAP25_rs2327264, and STX1A_rs6951030. The involvement of these genes, which are constituents of the SNARE complex involved in membrane fusion and neurotransmitter release, underscores their significance in migraine pathogenesis. Our reporter gene assays confirmed the impact of at least two of these non-coding variants. VAMP2 and SNAP25 risk alleles were associated with a decrease and increase in gene expression, respectively, while STX1A risk allele showed a tendency to reduce luciferase activity in neuronal-like cells. Therefore, the VAMP2_rs1150 and SNAP25_rs2327264 non-coding variants affect gene expression, which may have implications in migraine susceptibility. Based on previous in silico analysis, it is plausible that these variants influence the binding of regulators, such as transcription factors and micro-RNAs. Still, further studies exploring these mechanisms would be important to shed light on the association between SNAREs dysregulation and migraine susceptibility.

Comparison of East-Asia and West-Europe cohorts explains disparities in survival outcomes and highlights predictive biomarkers of early gastric cancer aggressiveness.

Surgical resection with lymphadenectomy and perioperative chemotherapy is the universal mainstay for curative treatment of gastric cancer (GC) patients with locoregional disease. However, GC survival remains asymmetric in West- and East-world regions. We hypothesize that this asymmetry derives from differential clinical management. Therefore, we collected chemo-naïve GC patients from Portugal and South Korea to explore specific immunophenotypic profiles related to disease aggressiveness and clinicopathological factors potentially explaining associated overall survival (OS) differences. Clinicopathological and survival data were collected from chemo-naïve surgical cohorts from Portugal (West-Europe cohort [WE-C]; n = 170) and South Korea (East-Asia cohort [EA-C]; n = 367) and correlated with immunohistochemical expression profiles of E-cadherin and CD44v6 obtained from consecutive tissue microarrays sections. Survival analysis revealed a subset of 12.4% of WE-C patients, whose tumors concomitantly express E-cadherin_abnormal and CD44v6_very high, displaying extremely poor OS, even at TNM stages I and II. These WE-C stage-I and -II patients tumors were particularly aggressive compared to all others, invading deeper into the gastric wall (P = .032) and more often permeating the vasculature (P = .018) and nerves (P = .009). A similar immunophenotypic profile was found in 11.9% of EA-C patients, but unrelated to survival. Tumours, from stage-I and -II EA-C patients, that display both biomarkers, also permeated more lymphatic vessels (P = .003), promoting lymph node (LN) metastasis (P = .019), being diagnosed on average 8 years earlier and submitted to more extensive LN dissection than WE-C. Concomitant E-cadherin_abnormal/CD44v6_very-high expression predicts aggressiveness and poor survival of stage-I and -II GC submitted to conservative lymphadenectomy.

A review of migraine genetics: gathering genomic and transcriptomic factors.

Migraine is a common and complex neurologic disorder that affects approximately 15-18% of the general population. Although the cause of migraine is unknown, some genetic studies have focused on unravelling rare and common variants underlying the pathophysiological mechanisms of this disorder. This review covers the advances in the last decade on migraine genetics, throughout the history of genetic methodologies used, including recent application of next-generation sequencing techniques. A thorough review of the literature interweaves the genomic and transcriptomic factors that will allow a better understanding of the mechanisms underlying migraine pathophysiology, concluding with the clinical utility landscape of genetic information and future consideration to creating a new frontier toward advancing the field of personalized medicine.

Lumbosacral transitional vertebrae: prevalence in a southern European population and its association with low back pain.

PURPOSE: Lumbosacral transitional vertebra (LSTV) is a congenital anomaly of the lumbosacral junction. Its prevalence is variable in the literature such as its association with low back pain. The aim of this study was to identify the prevalence of LSTV in a southern European population, and its correlation with low back pain. METHODS: A retrospective review of 639 thoraco-abdomino-pelvic consecutive CT-scans between January 2019 and November 2020 was performed. The presence of LSTV was classified into type II, III, IV based on Castellvi's classification. To investigate the association with low back pain, Oswestry Low Back Disability Questionnaire (ODI) and the EuroQol-5D-3L questionnaire was applied. RESULTS: The prevalence of LSTV was 24.9% (142 of 571). 37,3% were type IIb, 31,0% were type IIa, 13,4% were type IIIa, 9.9% were type IIIb and 8.5% were type IV. Individuals with LSTV were more likely to report low back pain and have a higher ODI score (OR:0.392, 95% CI:0.192-0.802, p = 0.010), (OR: 1050, 95% CI: 1029-1072, p < 0.01). Castellvi's type IV showed a significantly higher ODI when compared to type II (OR:1059, 95% CI:1019-1100, p = 0,04). There was no statistical difference in the EuroQol-5D-3L score between two groups (OR:1085, 95% CI: 0.459-2.560, p = 0.852). CONCLUSION: This population-based study adds to the literature the prevalence of LSTV in a southern European population. LSTV was associated with low back pain. However, this difference did not translate into a loss of quality life. Type IV was associated with higher functional disability when compared with type II.

Tuberculosis in the intensive care unit: alternative treatment regimens and association with mortality.

OBJECTIVES: Adequate anti-tuberculosis (TB) treatment is an important factor that can affect the patient's outcome. Higher mortality is found in patients who do not receive optimal treatment that includes isoniazid and rifampicin. The objective of this study is to evaluate the association of use of alternative TB treatment regimens (without rifampicin and isoniazid) and mortality among patients requiring intensive care. METHODS: Retrospective cohort study, from January 2010 to December 2018. Patients aged > 18 years with a TB diagnosis, admitted to the ICU of a general, tertiary care, university-affiliated hospital (Hospital de Clínicas de Porto Alegre - HCPA) were included. Data on TB treatment used and outcomes of treatment were collected. RESULTS: 462 patients met the inclusion criteria and were included in the analysis; 284 used the usual treatment regimen (rifampicin, isoniazid, pyrazinamide and ethambutol - all orally), and 178 used alternative treatment regimens (IV levofloxacin plus oral ethambutol plus IM streptomycin or IV amikacin, without rifampicin and isoniazid). The mortality was higher among users of alternative treatment regimens (63.5%) than among usual treatment regimen users (51.4%) (P = 0.011). In a multivariate analysis, age, albumin and death were independently associated with alternative treatment regimens use. CONCLUSIONS: TB programmes in which IV rifampicin is not widely available should consider including it, especially for critically ill TB patients, for whom there may be improved survival.

OBJECTIFS: Un traitement antituberculeux (TB) adéquat est un facteur important pouvant influencer les résultats du patient. Une mortalité plus élevée est observée chez les patients qui ne reçoivent pas un traitement optimal comprenant de l'isoniazide et de la rifampicine. L'objectif de cette étude est d'évaluer l'association entre l'utilisation d'autres schémas thérapeutiques anti-TB (sans rifampicine ni isoniazide) et la mortalité chez les patients nécessitant des soins intensifs. MÉTHODES: Etude de cohorte rétrospective, de janvier 2010 à décembre 2018. Les patients âgés de >18 ans avec un diagnostic de TB, admis à l'unité de soins intensifs d'un hôpital général, avec des soins tertiaires, affilié à l'Université (Hôpital de Clínicas de Porto Alegre-HCPA) ont été inclus. Des données sur le traitement anti-TB utilisé et les résultats du traitement ont été collectés. RÉSULTATS: 462 patients répondaient aux critères d'inclusion et ont été inclus dans l'analyse; 284 ont utilisé le schéma thérapeutique habituel (rifampicine, isoniazide, pyrazinamide et éthambutol - tous par voie orale) et 178 ont utilisé des schémas thérapeutiques alternatifs (lévofloxacine IV plus éthambutol oral plus streptomycine IM ou amikacine IV, sans rifampicine ni isoniazide). La mortalité était plus élevée chez les utilisateurs de schémas thérapeutiques alternatifs (63,5%) que chez les utilisateurs de schémas thérapeutiques habituels (51,4%) (P = 0,011). Dans l'analyse multivariée, l'âge, l'albumine et le décès ont été indépendamment associés à l'utilisation de schémas thérapeutiques alternatifs. CONCLUSIONS: Les programmes de lutte contre la TB dans lesquels la rifampicine IV n'est pas largement disponible devraient envisager de l'inclure, en particulier pour les patients atteints de TB et sévèrement malades, pour lesquels la survie peut être améliorée.

Cellular clearance of circulating transthyretin decreases cell-nonautonomous proteotoxicity in Caenorhabditis elegans.

Cell-autonomous and cell-nonautonomous mechanisms of neurodegeneration appear to occur in the proteinopathies, including Alzheimer's and Parkinson's diseases. However, how neuronal toxicity is generated from misfolding-prone proteins secreted by nonneuronal tissues and whether modulating protein aggregate levels at distal locales affects the degeneration of postmitotic neurons remains unknown. We generated and characterized animal models of the transthyretin (TTR) amyloidoses that faithfully recapitulate cell-nonautonomous neuronal proteotoxicity by expressing human TTR in the Caenorhabditis elegans muscle. We identified sensory neurons with affected morphological and behavioral nociception-sensing impairments. Nonnative TTR oligomer load and neurotoxicity increased following inhibition of TTR degradation in distal macrophage-like nonaffected cells. Moreover, reducing TTR levels by RNAi or by kinetically stabilizing natively folded TTR pharmacologically decreased TTR aggregate load and attenuated neuronal dysfunction. These findings reveal a critical role for in trans modulation of aggregation-prone degradation that directly affects postmitotic tissue degeneration observed in the proteinopathies.

A genetic interaction of NRXN2 with GABRE, SYT1 and CASK in migraine patients: a case-control study.

BACKGROUND: Migraine is a multifactorial disorder that is more frequent (two to four times) in women than in men. In recent years, our research group has focused on the role of neurotransmitter release and its regulation. Neurexin (NRXN2) is one of the components of the synaptic vesicle machinery, responsible for connecting intracellular fusion proteins and synaptic vesicles. Our aim was to continue exploring the role and interaction of proteins involved in the control and promotion of neurotransmission in migraine susceptibility. METHODS: A case-control study was performed comprising 183 migraineurs (148 females and 35 males) and 265 migraine-free controls (202 females and 63 males). Tagging single nucleotide polymorphisms of NRXN2 were genotyped to assess the association between NRXN2 and migraine susceptibility. The χ2 test was used to compare allele frequencies in cases and controls and odds ratios were estimated with 95% confidence intervals. Haplotype frequencies were compared between groups. Gene-gene interactions were analysed using the Multifactor Dimensionality Reduction v2.0. RESULTS: We found a statistically significant interaction model (p = 0.009) in the female group between the genotypes CG of rs477138 (NRXN2) and CT of rs1158605 (GABRE). This interaction was validated by logistic regression, showing a significant risk effect [OR = 4.78 (95%CI: 1.76-12.97)] after a Bonferroni correction. Our data also supports a statistically significant interaction model (p = 0.011) in the female group between the GG of rs477138 in NRXN2 and, the rs2244325's GG genotype and rs2998250's CC genotype of CASK. This interaction was also validated by logistic regression, with a protective effect [OR = 0.08 (95%CI: 0.01-0.75)]. A weak interaction model was found between NRXN2-SYT1. We have not found any statistically significant allelic or haplotypic associations between NRXN2 and migraine susceptibility. CONCLUSIONS: This study unravels, for the first time, the gene-gene interactions between NRXN2, GABRE - a GABAA-receptor - and CASK, importantly it shows the synergetic effect between those genes and its relation with migraine susceptibility. These gene interactions, which may be a part of a larger network, can potentially help us in better understanding migraine aetiology and in development of new therapeutic approaches.

Large normal alleles of ATXN2 decrease age at onset in transthyretin familial amyloid polyneuropathy Val30Met patients.

OBJECTIVE: Transthyretin (TTR)-related familial amyloid polyneuropathy (FAP) is an autosomal dominant neurological disease, caused most frequently by a Val30Met (now classified as Val50Met) substitution in TTR. Age at onset (AO) ranges from 19 to 82 years, and variability exists mostly between generations. Unstable oligonucleotide repeats in various genes are the mechanism behind several neurological diseases, found also to act as modifiers for other disorders. Our aim was to investigate whether large normal repeat alleles of 10 genes had a possible modifier effect in AO in Portuguese TTR-FAP Val30Met families. METHODS: We analyzed 329 Portuguese patients from 123 families. Repeat length (at ATXN1, ATXN2, ATXN3, ATXN7, TBP, ATN1, HTT, JPH3, AR, and DMPK) was assessed by single and multiplex polymerase chain reaction, using fluorescently labeled primers, followed by capillary electrophoresis. We used a family-centered approach, and generalized estimating equations were used to account for AO correlation between family members. RESULTS: For ATXN2, the presence of at least 1 allele longer than 22 CAGs was significantly associated with an earlier onset in TTR-FAP Val30Met, decreasing mean AO by 6 years (95% confidence interval = -8.81 to -2.19, p = 0.001). No association was found for the remaining repeat loci. INTERPRETATION: Length of normal repeats at ATXN2 may modify AO in TTR-FAP Val30Met and may function as a risk factor. This can be due to the role of ATXN2 in RNA metabolism and as a modulator of various cellular processes, including mitochondrial stress. This may have relevant implications for prognosis and the follow-up of presymptomatic carriers. ANN NEUROL 2019;85:251-258.

Going Deep into Synaptic Vesicle Machinery Genes and Migraine Susceptibility - A Case-Control Association Study.

OBJECTIVE: A number of observations, including among our study population, have implicated variants in the syntaxin-1A, a component of the synaptic vesicles, in migraine susceptibility. Therefore, we hypothesize that variants in other components of the vesicle machinery are involved in migraine. BACKGROUND: Migraine is a common and complex neurologic disorder that affects approximately 15-18% of the general population. The exact cause of migraine is unknown; however, genetic studies have made possible substantial progress toward the identification of underlying molecular pathways. Neurotransmitters have been for long considered to have a key role in migraine pathophysiology; so we investigated common variants in genes involved in the synaptic vesicle machinery and their impact in migraine susceptibility. METHODS: We performed a case-control study comprising 188 unrelated patients with headache and 286 healthy controls in a population from the north of Portugal. Benefiting from the presence of linkage disequilibrium, we selected and genotyped 119 tagging single-nucleotide polymorphisms in 18 genes. RESULTS: We found significant associations between single-nucleotide variants and migraine in 7 genes, SYN1, SYN2, SNAP25, VAMP2, STXBP1, STXBP5, and UNC13A, either conferring an increased risk or protection of migraine. Due to SYN1 X-chromosomal location, we performed the statistical analysis separated by gender and, in the female group, the C allele of rs5906435 increased the risk for migraine susceptibility (P = .021; OR = 1.69; 95% CI: 1.21-2.34). In contrast, the TT genotype of the same variant emerged as a potential protective factor (P = .003; OR = 0.45; 95% CI: 0.27-0.74). The SYN2 analysis supported the rs3773364's G allele (P = .014) as a risk factor for migraine, and although not statistically significant after correction, the AG genotype (P = .006; OR = 1.86; 95% CI: 1.20-2.90) reinforced the allelic findings. Additionally, we found the SNAP25-rs363039's CT genotype (P = .001; OR = 2.14; 95% CI: 1.36-3.34), the STXBP5-rs1765028's T allele (P = .041; OR = 1.46; 95% CI: 1.13-1.90), and the UNC13B-rs7851161's TT genotype (P = .001; OR = 2.14; 95% CI: 1.36-3.34) as statistically significant risk factors for migraine liability. VAMP2-rs1150's G allele revealed a risk association to migraine, not statistically significant after correction (P = .068). Additionally, we found haplotypes in SYN1, SYN2, STXBP1, and UNC13B to be associated with migraine. CONCLUSIONS: Overall, this study provides a new insight into migraine liability, identifying possible starting points for functional studies.

mtDNA copy number associated with age of onset in familial amyloid polyneuropathy.

BACKGROUND: Transthyretin-related familial amyloid polyneuropathy (TTR-FAP Val30Met) shows a wide variation in age-at-onset (AO) between generations and genders, as in Portuguese families, where women display a later onset and a larger anticipation (>10 years). Mitochondrial DNA (mtDNA) copy number was assessed to clarify whether it has a modifier effect on AO variability in Portuguese patients. METHODS: The mtDNA copy number of 262 samples (175 Val30Met TTR carriers and 87 controls (proven Val30Val)) was quantified by quantitative real-time PCR. Statistical analysis was performed using IBM SPSS V.23 software. RESULTS: This study shows that Val30Met TTR carriers have a significantly higher (p<0.001) mean mtDNA copy number than controls. Furthermore, the highest mtDNA copy number mean was observed in early-onset patients (AO <40 years). Importantly, early-onset offspring showed a significant increase (p=0.002) in the mtDNA copy number, when compared with their late AO parents. CONCLUSIONS: The present findings suggest, for the first time, that mtDNA copy number may be associated with earlier events and may therefore be further explored as a potential biomarker for follow-up of TTR-FAP Val30Met carriers.

Overcoming artefact: anticipation in 284 Portuguese kindreds with familial amyloid polyneuropathy (FAP) ATTRV30M.

BACKGROUND: Early-onset (≤40 years) and later-onset (≥50 years) cases of familial amyloid polyneuropathy (FAP) ATTRV30M are not different entities, often coexisting in the same family, and showing anticipation (earlier age-at-onset (AO) in younger generations, usually associated with more severe phenotype). Historically, anticipation has been ascribed to ascertainment biases. Our aim was to study anticipation in a very large number of FAP kindreds, removing possible biases, and gain further insight into parent-of-origin effects. METHODS: We analysed 926 parent-offspring pairs (from the Unidade Clínica de Paramiloidose roster, collected in 70 years), both clinically observed and had well-established AO, correcting for intrafamilial correlations. RESULTS: Women had a significantly higher AO, either for daughters (mean: 33.70, SD: 6.84) vs sons (29.43, 6.08); or mothers (39.57, 11.75) vs. fathers (35.62, 11.62). Also, 291 pairs showed marked anticipation (≥10 years); the transmitting parent was the mother in 203 pairs. Mother-son pairs showed larger anticipation (10.43, 9.34), while father-daughter pairs showed only a residual anticipation (1.23, 9.77). Gender of offspring and parents was highly significant (with no interaction). To remove possible biases, we repeated analyses: (1) excluding the proband; (2) removing pairs with simultaneous onset; and (3) excluding offspring born after 1960. Anticipation was found in all subsamples, with the same trend for a parent-of-origin effect. Noteworthy, parents with AO ≤40 years never had offspring with AO ≥50. CONCLUSIONS: These findings confirm anticipation as a true biological phenomenon, also in FAP ATTRV30M. Acknowledgment of anticipation may have important clinical implications in genetic counselling of offspring and in follow-up of mutation carriers.

Familial hemiplegic migraine due to L263V SCN1A mutation: discordance for epilepsy between two kindreds from Douro Valley.

BACKGROUND: SCN1A is the most relevant gene in epilepsy. Only seven SCN1A mutations have been identified in 10 familial hemiplegic migraine (FHM) kindreds worldwide. CASES AND KINDREDS: In 2009, we presented a kindred with FHM due to the L263V SCN1A mutation. In the current study, we report a novel FHM3 kindred from the same village. The first family exhibited the co-occurrence of FHM and epilepsy. No case of epilepsy was observed in the new kindred. An L263V mutation was found in all patients, and the haplotype analysis supports a unique mutational event. COMMENTS: Despite its bioelectric activity, the SCN1A L263V mutation most likely requires a combination of several endogenous or environmental induction stimuli to attain an epileptogenic threshold.

Sit4 Genetically Interacts with Vps27 to Regulate Mitochondrial Function and Lifespan in Saccharomyces cerevisiae.

The Sit4 protein phosphatase plays a key role in orchestrating various cellular processes essential for maintaining cell viability during aging. We have previously shown that SIT4 deletion promotes vacuolar acidification, mitochondrial derepression, and oxidative stress resistance, increasing yeast chronological lifespan. In this study, we performed a proteomic analysis of isolated vacuoles and yeast genetic interaction analysis to unravel how Sit4 influences vacuolar and mitochondrial function. By employing high-resolution mass spectrometry, we show that sit4Δ vacuolar membranes were enriched in Vps27 and Hse1, two proteins that are part of the endosomal sorting complex required for transport-0. In addition, SIT4 exhibited a negative genetic interaction with VPS27, as sit4∆vps27∆ double mutants had a shortened lifespan compared to sit4∆ and vps27∆ single mutants. Our results also show that Vps27 did not increase sit4∆ lifespan by improving protein trafficking or vacuolar sorting pathways. However, Vps27 was critical for iron homeostasis and mitochondrial function in sit4∆ cells, as sit4∆vps27∆ double mutants exhibited high iron levels and impaired mitochondrial respiration. These findings show, for the first time, cross-talk between Sit4 and Vps27, providing new insights into the mechanisms governing chronological lifespan.

Global DNA methylation is not elevated in blood samples from Machado-Joseph disease mutation carriers.

Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia (SCA) caused by a polyglutamine expansion in the ataxin-3 protein, which initiates a cascade of pathogenic events, including transcriptional dysregulation. Genotype-phenotype correlations in MJD are incomplete, suggesting an influence of additional factors, such as epigenetic modifications, underlying the MJD pathogenesis. DNA methylation is known to impact the pathophysiology of neurodegenerative disorders through gene expression regulation and increased methylation has been reported for other SCAs. In this work we aimed to analyse global methylation in MJD carriers. Global 5-mC levels were quantified in blood samples of 33 MJD mutation carriers (patients and preclinical subjects) and 33 healthy controls, matched by age, sex, and smoking status. For a subset of 16 MJD subjects, a pilot follow-up analysis with two time points was also conducted. No differences were found in median global 5-mC levels between MJD mutation carriers and controls and no correlations between methylation levels and clinical or genetic variables were detected. Also, no alterations in global 5-mC levels were observed over time. Our findings do not support an increase in global blood methylation levels associated with MJD.

Vertical Dentofacial Skeletal Divergency Is Not Linked with Oral Health-Related Quality of Life.

The aim of this study is to assess how vertical skeletal malocclusion affects oral health-related quality of life (OHRQoL) among a sample of individuals comprising adolescents, young adults, and adults seeking orthodontic treatment. From January 2019 to March 2020, participants were consecutively enrolled. The assessment of OHRQoL involved measurement using the oral health impact profile (OHIP-14). Lateral cephalograms were performed to measure the vertical skeletal divergency with four cephalometric measurements. Descriptive and inferential statistical analyses were performed. The Mann-Whitney test was applied to compare OHRQoL scores according to the vertical dimension category. The mean age of the participants ranged between 30.3 ± 14.9 and 29.9 ± 14.4 and there was a majority of female participants, between 64.1% and 65.9%. There were no statistically significant differences observed between hyperdivergent and normodivergent groups in either the total score or any domain of the OHIP-14 questionnaire. Individuals with hyperdivergent facial morphology did not show a reduced OHRQoL compared with a normodivergent facial type.

Hereditary transthyretin amyloidosis: a myriad of factors that influence phenotypic variability.

Hereditary transthyretin-related amyloidosis (ATTRv amyloidosis) is a rare and progressively debilitating disease characterized by the deposition of transthyretin (TTR) amyloid fibrils in various organs and tissues, most commonly in the heart and peripheral nerves. This pathological deposition can lead to significant organ dysfunction and, ultimately, organ failure. ATTRv amyloidosis exhibits a broad range of clinical presentations, from purely neurological symptoms to purely cardiac manifestations, as well as mixed phenotypes which result from both neurological and cardiac implications. This wide phenotypical spectrum realistically challenges disease diagnosis and prognosis, especially in individuals without or with an unknown family history. Multiple factors are thought to contribute to this variability, including genetic, epigenetic, and even environmental influences. Understanding these factors is crucial, as they can significantly affect disease expression and progression. This review aims to summarize each of these contributing factors, to help elucidate the current knowledge on the phenotypical variability of ATTRv amyloidosis.