Is Parkinson's disease of early onset a separate disease entity?

Two groups of patients suffering from Parkinson's disease were studied. The first group consisted of 23 patients with an onset age before 40 years; in the second group of 21 patients the onset was after age 50. The clinical findings and the course of the disease were very similar in each group. In spite of a longer disease duration in the patients with early onset of the disease there was no difference in motor impairment; the younger patients did better in mental testing and they were taking less dopaminergic medication. These differences are thought to be due to the age difference rather than to the existence of different disease entities. In the early onset group more familial cases (mostly affecting siblings) were found than in the older ones. The points in favour of there being a hereditary subgroup of early onset Parkinson's disease or of environmental factors causing the disease are reviewed.

Polymorphisms in MIR27A Associated with Early-Onset Toxicity in Fluoropyrimidine-Based Chemotherapy

PURPOSE The microRNA miR-27a was recently shown to directly regulate dihydropyrimidine dehydrogenase (DPD), the key enzyme in fluoropyrimidine catabolism. A common polymorphism (rs895819A>G) in the miR-27a genomic region (MIR27A) was associated with reduced DPD activity in healthy volunteers, but the clinical relevance of this effect is still unknown. Here, we assessed the association of MIR27A germline variants with early-onset fluoropyrimidine toxicity. EXPERIMENTAL DESIGN MIR27A was sequenced in 514 patients with cancer receiving fluoropyrimidine-based chemotherapy. Associations of MIR27A polymorphisms with early-onset (cycles 1-2) fluoropyrimidine toxicity were assessed in the context of known risk variants in the DPD gene (DPYD) and additional covariates associated with toxicity. RESULTS The association of rs895819A>G with early-onset fluoropyrimidine toxicity was strongly dependent on DPYD risk variant carrier status (Pinteraction = 0.0025). In patients carrying DPYD risk variants, rs895819G was associated with a strongly increased toxicity risk [OR, 7.6; 95% confidence interval (CI), 1.7-34.7; P = 0.0085]. Overall, 71% (12/17) of patients who carried both rs895819G and a DPYD risk variant experienced severe toxicity. In patients without DPYD risk variants, rs895819G was associated with a modest decrease in toxicity risk (OR, 0.62; 95% CI, 0.43-0.9; P = 0.012). CONCLUSIONS These results indicate that miR-27a and rs895819A>G may be clinically relevant for further toxicity risk stratification in carriers of DPYD risk variants. Our data suggest that direct suppression of DPD by miR-27a is primarily relevant in the context of fluoropyrimidine toxicity in patients with reduced DPD activity. However, miR-27a regulation of additional targets may outweigh its effect on DPD in patients without DPYD risk variants.

Variation in Current Management of Term and Late-Preterm Neonates at Risk for Early-Onset Sepsis "An International Survey and Review of Guidelines"

BACKGROUND Uncertainty about the presence of infection results in unnecessary and prolonged empiric antibiotic treatment of newborns at risk for early-onset sepsis (EOS). This study evaluates the impact of this uncertainty on the diversity in management. METHODS A web-based survey with questions addressing management of infection risk-adjusted scenarios was performed in Europe, North America, and Australia. Published national guidelines (n=5) were reviewed and compared to the results of the survey. RESULTS 439 Clinicians (68% were neonatologists) from 16 countries completed the survey. In the low-risk scenario, 29% would start antibiotic therapy and 26% would not, both groups without laboratory investigations; 45% would start if laboratory markers were abnormal. In the high-risk scenario, 99% would start antibiotic therapy. In the low-risk scenario, 89% would discontinue antibiotic therapy before 72 hours. In the high-risk scenario, 35% would discontinue therapy before 72 hours, 56% would continue therapy for five to seven days, and 9% for more than 7 days. Laboratory investigations were used in 31% of scenarios for the decision to start, and in 72% for the decision to discontinue antibiotic treatment. National guidelines differ considerably regarding the decision to start in low-risk and regarding the decision to continue therapy in higher risk situations. CONCLUSIONS There is a broad diversity of clinical practice in management of EOS and a lack of agreement between current guidelines. The results of the survey reflect the diversity of national guidelines. Prospective studies regarding management of neonates at risk of EOS with safety endpoints are needed.

The impact of ABCC11 polymorphisms on the risk of early-onset fluoropyrimidine toxicity

A missense variant (c.1637C>T, T546M) in ABCC11 encoding the MRP8 (multidrug resistance protein 8), a transporter of 5-fluorodeoxyuridine monophosphate, has been associated with an increased risk of 5-fluorouracil-related severe leukopenia. To validate this association, we investigated the impact of the ABCC11 variants c.1637C>T, c.538G>A and c.395+1087C>T on the risk of early-onset fluoropyrimidine-related toxicity in 514 cancer patients. The ABCC11 variant c.1637C>T was strongly associated with severe leukopenia in patients carrying risk variants in DPYD, encoding the key fluoropyrimidine-metabolizing enzyme dihydropyrimidine dehydrogenase (odds ratio (OR): 71.0; 95% confidence interval (CI): 2.5-2004.8; Pc.1637C>T*DPYD=0.013). In contrast, in patients without DPYD risk variants, no association with leukopenia (OR: 0.95; 95% CI: 0.34-2.6) or overall fluoropyrimidine-related toxicity (OR: 1.02; 95% CI: 0.5-2.1) was observed. Our study thus suggests that c.1637C>T affects fluoropyrimidine toxicity to leukocytes particularly in patients with high drug exposure, for example, because of reduced fluoropyrimidine catabolism.

EPA-0882 - Prediction of diagnosis of early-onset schizophrenia spectrum disorders using support vector machines

To develop a Support Vector Machine (SVM) algorithm as a predictive tool for diagnostic outcome in patients with FE-EOP, based on clinical and biomedical data at the emergence of the illness.

Unusual phenotypic alteration of β amyloid precursor protein (βAPP) maturation by a new Val-715 → Met βAPP-770 mutation responsible for probable early-onset Alzheimer’s disease

We have identified a novel β amyloid precursor protein (βAPP) mutation (V715M-βAPP770) that cosegregates with early-onset Alzheimer’s disease (AD) in a pedigree. Unlike other familial AD-linked βAPP mutations reported to date, overexpression of V715M-βAPP in human HEK293 cells and murine neurons reduces total Aβ production and increases the recovery of the physiologically secreted product, APPα. V715M-βAPP significantly reduces Aβ40 secretion without affecting Aβ42 production in HEK293 cells. However, a marked increase in N-terminally truncated Aβ ending at position 42 (x-42Aβ) is observed, whereas its counterpart x-40Aβ is not affected. These results suggest that, in some cases, familial AD may be associated with a reduction in the overall production of Aβ but may be caused by increased production of truncated forms of Aβ ending at the 42 position.

Dedicated Roles of Plastid Transketolases during the Early Onset of Isoprenoid Biogenesis in Pepper Fruits1

Isopentenyl diphosphate (IPP), which is produced from mevalonic acid or other nonmevalonic substrates, is the universal precursor of isoprenoids in nature. Despite the presence of several isoprenoid compounds in plastids, enzymes of the mevalonate pathway leading to IPP formation have never been isolated or identified to our knowledge. We now describe the characterization of two pepper (Capsicum annuum L.) cDNAs, CapTKT1 and CapTKT2, that encode transketolases having distinct and dedicated specificities. CapTKT1 is primarily involved in plastidial pentose phosphate and glycolytic cycle integration, whereas CapTKT2 initiates the synthesis of isoprenoids in plastids via the nonmevalonic acid pathway. From pyruvate and glyceraldehyde-3-phosphate, CapTKT2 catalyzes the formation of 1-deoxy-xylulose-5-phosphate, the IPP precursor. CapTKT1 is almost constitutively expressed during the chloroplast-to-chromoplast transition, whereas CapTKT2 is overexpressed during this period, probably to furnish the IPP necessary for increased carotenoid biosynthesis. Because deoxy-xylulose phosphate is shared by the plastid pathways of isoprenoid, thiamine (vitamin B1), and pyridoxine (vitamin B6) biosynthesis, our results may explain why albino phenotypes usually occur in thiamine-deficient plants.

Early-onset multifocal inflammation in the transforming growth factor beta 1-null mouse is lymphocyte mediated.

Transforming growth factor beta 1 (TGF beta 1)-null mice die fro complications due to an early-onset multifocal inflammatory disorder. We show here that cardiac cells are hyperproliferative and that intercellular adhesion molecule 1 (ICAM-1) is elevated. To determine which phenotypes are primarily caused by a deficiency in TGF beta 1 from those that are secondary to inflammation, we applied immunosuppressive therapy and genetic combination with the severe combined immunodeficiency (SCID) mutation to inhibit the inflammatory response. Treatment with antibodies to the leukocyte function-associated antigen 1 doubled longevity, reduced inflammation, and delayed heart cell proliferation. TGF beta 1-null SCID mice displayed no inflammation or cardiac cell proliferation, survived to adulthood, and exhibited normal major histocompatibility complex II (MHC II) and ICAM-1 levels. TGF beta 1-null pups born to a TGF beta 1-null SCID mother presented no gross congenital heart defects, indicating that TGF beta 1 alone does not play an essential role in heart development. These results indicate that lymphocytes are essential for the inflammatory response, cardiac cell proliferation, and elevated MHC II and ICAM-1 expression, revealing a vital role for TGF beta 1 in regulating lymphocyte proliferation and activation, which contribute to the maintenance of self tolerance.

Major Depressive Disorder, Suicidal Ideation, and Suicide Attempt in Twins Discordant for Cannabis Dependence and Early-Onset Cannabis Use

Background: Previous research has reported both a moderate degree of comorbidity between cannabis dependence and major depressive disorder (MDD) and that early-onset cannabis use is associated with increased risks for MDD. Objective: To examine whether associations between both lifetime cannabis dependence and early cannabis use and measures of MDD, suicidal ideation, and suicide attempt persist after controlling for genetic and/or shared environmental influences. Design: Cross-sectional survey of twin pairs discordant for lifetime cannabis dependence and those discordant for early cannabis use. Setting: General population sample of twins (median age, 30 years). Participants: Two hundred seventy-seven same-sex twin pairs discordant for cannabis dependence and 311 pairs discordant for early-onset cannabis use (before age 17 years). Main Outcome Measures: Self-report measures of DSM-IV-defined lifetime MDD, suicidal ideation, and suicide attempt. Results: Individuals who were cannabis dependent had odds of suicidal ideation and suicide attempt that were 2.5 to 2.9 times higher than those of their non-cannabis-dependent co-twin. Additionally, cannabis dependence was associated with elevated risks of MDD in dizygotic but not in monozygotic twins. Those who initiated cannabis use before age 17 years had elevated rates of subsequent suicide attempt (odds ratio, 3.5 [95% confidence interval, 1.4-8.6]) but not of MDD or suicidal ideation. Early MDD and suicidal ideation were significantly associated with subsequent risks of cannabis dependence in discordant dizygotic pairs but not in discordant monozygotic pairs. Conclusions: Comorbidity between cannabis dependence and MDD likely arises through shared genetic and environmental vulnerabilities predisposing to both outcomes. In contrast, associations between cannabis dependence and suicidal behaviors cannot be entirely explained by common predisposing genetic and/or shared environmental predispositions. Previously reported associations between early-onset cannabis use and subsequent MDD likely reflect shared genetic and environmental vulnerabilities, although it remains possible that early-onset cannabis use may predispose to suicide attempt.

Histopathology and fibrillin-1 distribution in severe early onset Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant condition which may involve the cardiovascular, ocular, skeletal, and other systems. Mutations causing MFS are found in the FBN1 gene, encoding fibrillin-1, an extracellular matrix protein involved in microfibril formation. In the most severe cases, mutations are generally found in exons 24-32, and children with these mutations usually die in the first years of life, of cardiopulmonary failure. We present clinical, molecular and histopathological studies on a patient with severe early onset MFS. He has a mutation in exon 25 of FBN1, a G > A transition at nucleotide position 3131 that converts the codon TGC, coding for cysteine at position 1044, to TAC, coding for tyrosine (C1044Y). This has resulted in abnormalities of the extracellular matrix and a severe clinical phenotype, although he has survived to the age of 14 years. (c) 2005 Wiley-Liss, Inc.

Congenital disorder of glycosylation type Ia presenting as early-onset cerebellar ataxia in an adult

Congenital disorders of glycosylation (CDG) are a recently described, underrecognized group of syndromes characterized biochemically by abnormal glycosylation of serum and cellular glycoproteins. We report a previously undiagnosed adult male who presented with early-onset cerebellar ataxia in the context of mental impairment, peripheral neuropathy, retinopathy, body dysmorphism, cardiomyopathy, and hypogonadism. Newly available screening and genetic testing confirmed the diagnosis as CDG type Ia. This case emphasizes that CDG should be considered as a differential diagnosis for adults with early-onset cerebellar ataxia, particularly in those persons with the aforementioned features, and that undiagnosed cases of childhood ataxia may require reassessment now that testing is available. © 2006 Movement Disorder Society

Spatial correlations between beta-amyloid (Abeta) deposits and blood vessels in early-onset Alzheimer's disease

In cases of late-onset Alzheimer’s disease (AD), there is a spatial correlation between the classsic ‘cored’ type of Beta-amyloid (Abeta) deposit and the large vertically penetrating arterioles in the cerebral cortex suggesting that blood vessels are involved in the pathogenesis of the classic deposits. In this chapter, the spatial correlations between the diffuse, primitive, and classic Abeta deposits and blood vessels were studied in 10 cases of early-onset AD in the age range 40 – 65 years. Sections of frontal cortex were immunostained with antibodies against Abeta?and with collagen IV to reveal the Abeta deposits and blood vessel profiles. In the early-onset cases as a whole, all types of Abeta? deposit and blood vessel profiles were distributed in clusters. There was a positive spatial correlation between the clusters of the diffuse Abeta deposits and the larger (>10µm) and smaller diameter (<10?m) blood vessel profiles in one and three cases respectively. The primitive and classic Abeta deposits were spatially correlated with larger and smaller blood vessels both in three and four cases respectively. Spatial correlations between the Abeta deposits and blood vessels may be more prevalent in cases expressing amyloid precursor protein (APP) than presenilin 1 (PSEN1) mutations. Apolipoprotein E (Apo E) genotype of the patient did not appear to influence the spatial correlation with blood vessel profiles. The data suggest that the larger diameter blood vessels are less important in the pathogenesis of the classic Abeta deposits in early-onset compared with late-onset AD.

The Maudsley Early Onset Schizophrenia Study:The effect of age of onset and illness duration on fronto-parietal gray matter

Objective: In Early Onset Schizophrenia (EOS; onset before the 18th birthday) late brain maturational changes may interact with disease mechanisms leading to a wave of back to front structural changes during adolescence. To further explore this effect we examined the relationship between age of onset and duration of illness on brain morphology in adolescents with EOS. Subjects and methods: Structural brain magnetic resonance imaging scans were obtained from 40 adolescents with EOS. We used Voxel Based Morphometry and multiple regressions analyses, implemented in SPM, to examine the relationship between gray matter volume with age of onset and illness duration. Results: Age of onset showed a positive correlation with regional gray matter volume in the right superior parietal lobule (Brodmann Area 7). Duration of illness was inversely related to regional gray matter volume in the left inferior frontal gyrus (BA 11/47). Conclusions: Parietal gray matter loss may contribute to the onset of schizophrenia while orbitofrontal gray matter loss is associated with illness duration. © 2008 Elsevier Masson SAS. All rights reserved.