Article

A novel PSEN2 mutation associated with a peculiar phenotype

Istituto Superiore di Sanità, 00161 Rome, Italy.
Neurology (Impact Factor: 8.3). 05/2008; 70(17):1549-54. DOI: 10.1212/01.wnl.0000310643.53587.87
Source: PubMed

ABSTRACT Mutations of presenilin 2 gene are a rare cause of familial Alzheimer disease (AD). We describe an Italian family with hereditary dementia associated with a novel mutation in the presenilin 2 gene.
Clinical investigations of the diseased subjects; interviews with relatives; studies of medical records; pedigree analysis; and neuroradiologic, neuropathologic, and molecular genetic studies were carried out in the pedigree.
Genetic analysis showed a novel PSEN2 A85V mutation present in the proband and in all analyzed affected members, in a subject presenting with an amnesic mild cognitive impairment, and in a young, still asymptomatic subject. The proband showed a clinical phenotype indicative of Lewy body dementia and the neuropathologic examination demonstrated the presence of unusually abundant and widespread cortical Lewy bodies in addition to the hallmark lesions of AD. Other affected members exhibited a clinical phenotype typical of AD.
Our findings add complexity to the spectrum of atypical phenotypes associated with presenilin mutations and should then be taken into account when considering the nosography of neurodegenerative diseases. They also support previous data that specific mutations of genes associated with familial Alzheimer disease may influence the presence and extent of Lewy bodies.

0 Followers
 · 
125 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mutations in the gene PSEN2 are a rare cause of early onset Alzheimer's disease (EOAD). PSEN2 sequence variants are often only found in one patient and pathogenicity cannot be formally documented. Here we describe a previously unrecognized sequence change (c.376G>A) in PSEN2 in an EOAD patient and her likewise affected mother. This change results in the exchange of amino acid glutamic acid (E) by lysine (K) at position 126 of the protein (p.E126K). Pathogenicity of the mutation is shown by segregation with disease, evolutionary conservation of E126, and in silico analysis of the mutation.
    Journal of Alzheimer's disease: JAD 05/2014; 42(1). DOI:10.3233/JAD-140399 · 3.61 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: An increasing number of hereditary neurodegenerative diseases, including autosomal-dominant Alzheimer disease (AD), familial autosomal-dominant frontotemporal dementia (FTD), and heritable Lewy body disease (LBD) have been defined at the molecular level in recent years, making it possible to determine the genotype before the onset of symptoms. The identification of deterministic genes for these common adult-onset genetic diseases is moving the field of genetic counseling toward a new and challenging direction. With the identification of genes associated with AD and FTD, there is considerable interest in the clinical application of genetic information in genetic counseling and testing. Progress in the genetics of dementing disorders and the availability of clinical tests for practicing physicians therefore increases the need for a better understanding of the multifaceted issues associated with genetic testing. The aims of this systematic review are: (1) to underline the need to consider a genetic etiology of AD, FTD, and LBD; (2) to provide clinicians with information necessary to effectively translate genetic diagnosis into clinical practice; and (3) to highlight gaps and uncertainties in the field which will need to be addressed by future research.
    Alzheimer disease and associated disorders 05/2014; DOI:10.1097/WAD.0000000000000046 · 2.69 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Alzheimer's disease (AD) is a complex and heterogeneous neurodegenerative disorder, classified as either early onset (under 65 years of age), or late onset (over 65 years of age). Three main genes are involved in early onset AD: amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2). The apolipoprotein E (APOE) E4 allele has been found to be a main risk factor for late-onset Alzheimer's disease. Additionally, genome-wide association studies (GWASs) have identified several genes that might be potential risk factors for AD, including clusterin (CLU), complement receptor 1 (CR1), phosphatidylinositol binding clathrin assembly protein (PICALM), and sortilin-related receptor (SORL1). Recent studies have discovered additional novel genes that might be involved in late-onset AD, such as triggering receptor expressed on myeloid cells 2 (TREM2) and cluster of differentiation 33 (CD33). Identification of new AD-related genes is important for better understanding of the pathomechanisms leading to neurodegeneration. Since the differential diagnoses of neurodegenerative disorders are difficult, especially in the early stages, genetic testing is essential for diagnostic processes. Next-generation sequencing studies have been successfully used for detecting mutations, monitoring the epigenetic changes, and analyzing transcriptomes. These studies may be a promising approach toward understanding the complete genetic mechanisms of diverse genetic disorders such as AD.
    Clinical Interventions in Aging 04/2014; 9:535-551. DOI:10.2147/CIA.S51571 · 1.82 Impact Factor

Full-text

Download
118 Downloads
Available from
May 23, 2014