Mutations in three genes (PSEN1, PSEN2, and APP) have been identified in patients with early-onset (<65years) Alzheimer's disease (AD). We performed a screening for mutations in the coding regions of presenilins, as well as exons 16 and 17 of the APP gene in a total of 231 patients from the Iberian peninsular with a clinical diagnosis of early onset AD (mean age at onset of 52.9 years; range 31-64). We found three novel mutations in PSEN1, one novel mutation in PSEN2, and a novel mutation in the APP gene. Four previously described mutations in PSEN1 were also found. The same analysis was carried in 121 elderly healthy controls from the Iberian peninsular, and a set of 130 individuals NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript from seven African populations belonging to the Centre d'Etude du Polymorphisme Humain-Human Genome Diversity Panel (CEPH-HGDP), in order to determine the extent of normal variability in these genes. Interestingly, in the latter series, we found five new nonsynonymous changes in all three genes and a presenilin 2 variant (R62H) that has been previously related to AD. In some of these mutations, the pathologic consequence is uncertain and needs further investigation. To address this question we propose and use a systematic algorithm to classify the putative pathology of AD mutations.

Parvovirus B19 (PB19) is a common, widespread, small, single-stranded DNA virus which has been linked with a broad spectrum of clinical illnesses, including a variety of neurological complications such as encephalitis, meningitis, myelitis, stroke, cerebellar ataxia, and neuropathy. The authors describe a case of PB19 infection associated with hemolytic anemia and cranial polyneuropathy involving the second and third cranial nerves in a 23-year-old immunocompetent woman. The diagnosis of acute PB19 infection was established with detection of positive DNA and anti-PB19 IgM antibodies in blood samples. Antiganglioside antibody studies were performed and serum anti-GD1b IgG was strongly positive. Further investigation was normal or negative, excluding other infectious or autoimmune disorders. The patient was initially treated with a 5-day course of intravenous immunoglobulin (IGIV). Because of incomplete neurological recovery, methylprednisolone was also administered 7 days after IGIV therapy initiation. Complete resolution of clinical symptoms was observed 3 months after disease onset at follow-up visit, despite the persistence of PB19 DNA and anti-PB19 IgM antibodies in serum 5 months after the initial presentation. Our report provides evidence that PB19 could affect both the central and peripheral nervous system, possibly by triggering an autoimmune mechanism that leads to autoantibody production.

Spoligotyping was used in the genotyping of 219 isolates of the Mycobacterium tuberculosis complex, from patients of the Hospital Fernando Fonseca. This technique, based on PCR methodology, analyses a region of the chromosome specific of the Mycobacterium tuberculosis complex, the DR locus (Direct Repeat). With the aid of an international database, we showed that the predominant Spoligotypes belonged to the LAM family (Latino-American Mediterranean), 29.2 %. The LAM 9 family, with 12.3 %, left us attentive to the possible import of the disease through populations from South America, were it has been frequently identified. The genotypic families T1 and Haarlem, with 6.4 % and 8.7 % respectively, represented a frequency typical to Europe. The Beijing family, with 1.4 %, may represent an emerging problem in our country due to recent immigration of Asian and Eastern European populations. Isolates with a Spoligotype of the M. bovis type were found at a high percentage, 3.7 %. In Europe, this infection is extremely rare suggesting the result may not be due to M. bovis infection but to M. bovis BCG (due to vaccination or eventual recombinant BCG based therapies), or M. africanum (due to the proximity of the two species). A high percentage of the Spoligotypes were not identified by the database, 21.4 %. This is the first study of this type amongst us and may be the starting point for the creation of a data base with important consequences on the national program against tuberculosis.