Widespread Lewy body and tau accumulation in childhood and adult onset dystonia-parkinsonism cases with PLA2G6 mutations

AbstractThe 2 major types of neurodegeneration with brain iron accumulation (NBIA) are the pantothenate kinase type 2 (PANK2)-associated neurodegeneration (PKAN) and NBIA2 or infantile neuroaxonal dystrophy (INAD) due to mutations in the phospholipase A2, group VI (PLA2G6) gene. We have recently demonstrated clinical heterogeneity in patients with mutations in the PLA2G6 gene by identifying a poorly defined subgroup of patients who present late with dystonia and parkinsonism. We report the clinical and genetic features of 7 cases with PLA2G6 mutations. Brain was available in 5 cases with an age of death ranging from 8 to 36 years and showed widespread alpha-synuclein-positive Lewy pathology, which was particularly severe in the neocortex, indicating that the Lewy pathology spread corresponded to Braak stage 6 and was that of the “diffuse neocortical type”. In 3 cases there was hyperphosphorylated tau accumulation in both cellular processes as threads and neuronal perikarya as pretangles and neurofibrillary tangles. Later onset cases tended to have less tau involvement but still severe alpha-synuclein pathology. The clinical and neuropathological features clearly represent a link between PLA2G6 and parkinsonian disorders

Differential association of two PTPN22 coding variants with Crohn’s disease and ulcerative colitis

2 páginas.-- Póster presentado al 5º European Workshop on Immune-Mediated Inflammatory Diseases celebrado en Sitges (Barcelona) dxel 1 al 3 de Diciembre de 2010.-- et al.The PTPN22 gene is an important risk factor for human autoimmunity. Two PTPN22 missense-SNPs, both with functional influence, the R620W (1858C>T, rs2476601) in exon 14 and the R263Q (788G>A, rs33996649) in exon 10 have been associated with autoimmune diseases [1-4].Peer reviewe

A homologue of the Parkinson's disease-associated protein LRRK2 undergoes a monomer-dimer transition during GTP turnover.

Mutations in LRRK2 are a common cause of genetic Parkinson's disease (PD). LRRK2 is a multi-domain Roco protein, harbouring kinase and GTPase activity. In analogy with a bacterial homologue, LRRK2 was proposed to act as a GTPase activated by dimerization (GAD), while recent reports suggest LRRK2 to exist under a monomeric and dimeric form in vivo. It is however unknown how LRRK2 oligomerization is regulated. Here, we show that oligomerization of a homologous bacterial Roco protein depends on the nucleotide load. The protein is mainly dimeric in the nucleotide-free and GDP-bound states, while it forms monomers upon GTP binding, leading to a monomer-dimer cycle during GTP hydrolysis. An analogue of a PD-associated mutation stabilizes the dimer and decreases the GTPase activity. This work thus provides insights into the conformational cycle of Roco proteins and suggests a link between oligomerization and disease-associated mutations in LRRK2

Cooperative Genome-Wide Analysis Shows Increased Homozygosity in Early Onset Parkinson's Disease

Parkinson's disease (PD) occurs in both familial and sporadic forms, and both monogenic and complex genetic factors have been identified. Early onset PD (EOPD) is particularly associated with autosomal recessive (AR) mutations, and three genes, PARK2, PARK7 and PINK1, have been found to carry mutations leading to AR disease. Since mutations in these genes account for less than 10% of EOPD patients, we hypothesized that further recessive genetic factors are involved in this disorder, which may appear in extended runs of homozygosity

LRRK2 Phosphorylates Tubulin-Associated Tau but Not the Free Molecule: LRRK2-Mediated Regulation of the Tau-Tubulin Association and Neurite Outgrowth

Leucine-rich repeat kinase 2 (LRRK2), a large protein kinase containing multi-functional domains, has been identified as the causal molecule for autosomal-dominant Parkinson's disease (PD). In the present study, we demonstrated for the first time that (i) LRRK2 interacts with tau in a tubulin-dependent manner; (ii) LRRK2 directly phosphorylates tubulin-associated tau, but not free tau; (iii) LRRK2 phosphorylates tau at Thr181 as one of the target sites; and (iv) The PD-associated LRRK2 mutations, G2019S and I2020T, elevated the degree of tau-phosphorylation. These results provide direct proof that tau is a physiological substrate for LRRK2. Furthermore, we revealed that LRRK2-mediated phosphorylation of tau reduces its tubulin-binding ability. Our results suggest that LRRK2 plays an important role as a physiological regulator for phosphorylation-mediated dissociation of tau from microtubules, which is an integral aspect of microtubule dynamics essential for neurite outgrowth and axonal transport

LRP10 interacts with SORL1 in the intracellular vesicle trafficking pathway in non-neuronal brain cells and localises to Lewy bodies in Parkinson's disease and dementia with Lewy bodies

Loss-of-function variants in the low-density lipoprotein receptor-related protein 10 (LRP10) gene have been associated with autosomal-dominant Parkinson's disease (PD), PD dementia, and dementia with Lewy bodies (DLB). Moreover, LRP10 variants have been found in individuals diagnosed with progressive supranuclear palsy and amyotrophic lateral sclerosis. Despite this genetic evidence, little is known about the expression and function of LRP10 protein in the human brain under physiological or pathological conditions. To better understand how LRP10 variants lead to neurodegeneration, we first performed an in-depth characterisation of LRP10 expression in post-mortem brains and human-induced pluripotent stem cell (iPSC)-derived astrocytes and neurons from control subjects. In adult human brain, LRP10 is mainly expressed in astrocytes and neurovasculature but undetectable in neurons. Similarly, LRP10 is highly expressed in iPSC-derived astrocytes but cannot be observed in iPSC-derived neurons. In astrocytes, LRP10 is present at trans-Golgi network, plasma membrane, retromer, and early endosomes. Interestingly, LRP10 also partially co-localises and interacts with sortilin-related receptor 1 (SORL1). Furthermore, although LRP10 expression and localisation in the substantia nigra of most idiopathic PD and DLB patients and LRP10 variant carriers diagnosed with PD or DLB appeared unchanged compared to control subjects, significantly enlarged LRP10-positive vesicles were detected in a patient carrying the LRP10 p.Arg235Cys variant. Last, LRP10 was detected in Lewy bodies (LB) at late maturation stages in brains from idiopathic PD and DLB patients and in LRP10 variant carriers. In conclusion, high LRP10 expression in non-neuronal cells and undetectable levels in neurons of control subjects indicate that LRP10-mediated pathogenicity is initiated via cell non-autonomous mechanisms, potentially involving the interaction of LRP10 with SORL1 in vesicle trafficking pathways. Together with the specific pattern of LRP10 incorporation into mature LBs, these data support an important mechanistic role for disturbed vesicle trafficking and loss of LRP10 function in neurodegenerative diseases

Nonmotor Symptoms in LRRK2 G2019S Associated Parkinson's Disease

BACKGROUND: Idiopathic Parkinson's disease (IPD) and LRRK2-associated PD (LRRK2-PD) might be expected to differ clinically since the neuropathological substrate of LRRK2-PD is heterogeneous. The range and severity of extra-nigral nonmotor features associated with LRRK2 mutations is also not well-defined. OBJECTIVE: To evaluate the prevalence and time of onset of nonmotor symptoms (NMS) in LRRK2-PD patients. METHODS: The presence of hyposmia and of neuropsychiatric, dysautonomic and sleep disturbances was assessed in 33 LRRK2-G2019S-PD patients by standardized questionnaires and validated scales. Thirty-three IPD patients, matched for age, gender, duration of parkinsonism and disease severity and 33 healthy subjects were also evaluated. RESULTS: University of Pennsylvania Smell Identification Test (UPSIT) scores in LRRK2-G2019S-PD were higher than those in IPD (23.5±6.8 vs 18.4±6.0; p = 0.002), and hyposmia was less frequent in G2019S carriers than in IPD (39.4% vs 75.8%; p = 0.01). UPSIT scores were significantly higher in females than in males in LRRK2-PD patients (26.9±4.7 vs 19.4±6.8; p<0.01). The frequency of sleep and neuropsychiatric disturbances and of dysautonomic symptoms in LRRK2-G2019S-PD was not significantly different from that in IPD. Hyposmia, depression, constipation and excessive daytime sleepiness, were reported to occur before the onset of classical motor symptoms in more than 40% of LRRK2-PD patients in whom these symptoms were present at the time of examination. CONCLUSION: Neuropsychiatric, dysautonomic and sleep disturbances occur as frequently in patients with LRRK2-G2019S-PD as in IPD but smell loss was less frequent in LRRK2-PD. Like in IPD, disturbances such as hyposmia, depression, constipation and excessive daytime sleepiness may antedate the onset of classical motor symptoms in LRRK2-G2019S-PD

Epidermolysis bullosa (EB): Pathogenesis, clinical, diagnostic and genetic aspects, molecular basis, epidemiological aspects, management of patients with EB and translational implications of mutation analysis

Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCUnder the term "Epidermolysis Bullosa" (EB), there is a heterogeneous group of vesicular disorders that are generally congenital and of genetic origin, and affect skin and often mucosas. It is remarkable the extreme fragility of these epithelia; the vesicles arise spontaneously as well as induced by even slight trauma or the influence of high temperatures. Their content is sero-hemorrhagic and in the scarring can be very difficult. As a consecuence of the scarring processes, joint contractures and fusion of digits (pseudo-syndactyly) can occur. Pathogenetically, EB is caused by abnormal blistering at the basement membrane zone in the dermal-epidermal attachment zone and its surroundings. This is due to alterations in the attachment complexes, and some mutations have been identified in a total of 10 genes expressed in such level. Four main types of EB can be distinguished (simple, junctional, dystrophic and hemidesmosomal), depending on the level at which the cleavage that forms the bulla takes place, although about 30 subtypes have been described. The clinical characteristics or optic microscopy are not adequate for diagnosis, and it is mandatory to perform electron microscopy, immunofluorescent and immunohistochemical studies, as well as mutation analysis if available. Regarding the epidemiological aspects, in the Spanish Collaborative Study of Congenital Malformations (ECEMC), since 1976 up to December 2004, a total of 2,204,264 liveborn infants were controlled and, among them 27 cases have been identified, for a minimum frequency of 0.12 per 10,000 (95% confidence interval:0.08-0.18). It seems generally accepted that the determination of the frequency of EB is subject to multiple biases and registration of cases is always incomplete. We have also reviewed the issues related to management of EB patients by clinicians.N

Aspectos clínicos y epidemiológicos de los síndromes de Apert y Crouzon en España

Epidemiología y Teratología: Resultados sobre los datos del ECEMCApert and Crouzon syndromes are the most frequent ones among those syndromes with craniosynostosis. We have used data from the Spanish Collaborative Study of Congenital Malformations (ECEMC), to analyze some clinical and epidemiological characteristics of both syndromes. A total of 19 cases of Apert and 21 cases of Crouzon syndromes were identified among 1,914,726 liveborn infants. Their birth prevalence has diminished along the time although the decrease is only statistically significant for Crouzon syndrome. Mean parental ages, and mean differences between the parental ages, are significantly higher in Apert cases than in controls, what is indicating a relationship between paternal age and mutations for this syndrome. The differences between the parental ages of Crouzon cases and controls are not statistically significant. All the cases with Apert syndrome of our series were the first occurrence in the family, while 38.10% of the Crouzon cases were familial. We also observed a significant increasing linear trend in the frequency of infants with Apert syndrome, with the increasing paternal age, which is more noticeable since the age of 35 years. However, this is not observed for Crouzon cases whether sporadic or familial. Regarding the clinical aspects, Apert syndrome is more frequently associated to other defects than Crouzon syndrome. With respect to the affectation of hands in the Apert cases, the most frequent defect was the so-called "mitten hand", wich was present in 50% of our cases. In 28.57% the first finger was separated from the rest that are fused. Interestingly, in one case only the fifth finger was separated for the other four that remain fused.N

Diagnostic, etiologic, and genetic aspects of congenital ichthyoses at birth: Characteristics of the ECEMC cases

Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCThe Ichthyoses constitutes a large family of genetic skin diseases characterized by dry skin and variable degrees of blisters and scales. There are at least twenty varieties of ichthyosis, with a wide range of severity and associated symptoms, and genetic heterogeneity (autosomal dominant, autosomal recessive, and X-linked inheritance). The clinical symptoms, which are non-specific, may not be apparent. We have attempted to provide a classification of the ichthyoses and some guidance for the diagnosis and management of these conditions. The present classification is based in the type of alteration of the skin layer, the molecular findings, the biochemical characteristics, and the family history.There are three main categories, which include different subgroups of ichthyoses: 1) Those that are caused by an altered process of keratinocytic diferenciation (altered intermediate filaments/keratins). This category includes the following subgroups: a) Harlequin fetus; b) bullous erythroderma ichthyosiformis congenital; c) Ichthyosis bullosa of Siemens; d) Ichthyosis hystrix of Curth-Macklin; and e) Ichthyosis vulgaris. 2) Those that are caused by a deficient formation of the cornified envelope (transglutaminase 1 enzyme deficiency). In this category we include two main subgrups: a) Lamellar ichthyosis AR, which includes i) ichthyosis lamellar (IL1, IL2, IL3, IL4, and IL5), and ii) ichthyosiform erythroderma congenital nonbullous, and b) Nonlamellar ichthyosis and nonerythrodermic congenital ichthyosis AR. 3) Those caused by an abnormal steroid sulfatase (X-linked Ichtyosis). In spite of having only data at birth and the lack of molecular analysis, we attempted to classify the ECEMC cases according to this classification using available clinical data. We also calculated the frequency of this disease identified at birth, and provide some guidance for the clinical diagnosis, the management of the affected newborn, and the information that should be offered to the parents.N