Dementia-related genetic variants in an Italian population of early-onset Alzheimer’s disease

Early-onset Alzheimer’s disease (EOAD) is the most common form of early-onset dementia. Although three major genes have been identified as causative, the genetic contribution to the disease remains unsolved in many patients. Recent studies have identified pathogenic variants in genes representing a risk factor for developing Alzheimer’s disease (AD) and in causative genes for other degenerative dementias as responsible for EOAD. To study them further, we investigated a panel of candidate genes in 102 Italian EOAD patients, 45.10% of whom had a positive family history and 21.74% with a strong family history of dementia. We found that 10.78% of patients carried pathogenic or likely pathogenic variants, including a novel variant, in PSEN1, PSEN2, or APP, and 7.84% showed homozygosity for the ε4 APOE allele. Additionally, 7.84% of patients had a moderate risk allele in PSEN1, PSEN2, or TREM2 genes. Besides, we observed that 12.75% of our patients carried only a variant in genes associated with other neurodegenerative diseases. The combination of these variants contributes to explain 46% of cases with a definite familiarity and 32% of sporadic forms. Our results confirm the importance of extensive genetic screening in EOAD for clinical purposes, to select patients for future treatments and to contribute to the definition of overlapping pathogenic mechanisms between AD and other forms of dementia

Case report: the man in the farmhouse – Effective support of entomotoxicological exams to identify causes of death

At the end of April 2007, a male corpse was found inside a deserted farmhouse near Agliè, a small municipality in the district of Turin. The man didn’t have any identity documents on him and his body was in advance decay stage. He was found in a empty room of the farmhouse, he was wearing many layers of winter clothes and he was huddleded up on one side, lying on a plastic curtain. On the corpse and in the room there were plenty of necrophagous insects. For this reason, beside the autopsy, forensic entomological examinations were made. From the description of physical features as well as the clothes, we assumed that he might have been a man that went missing in February 2007, from an elderly residence. He was under psychotropic treatment. The pathological exams made also by X-rays didn’t detect any fractures or lesions which might have caused his death. The toxicological exams were made on hair sample of the victim as well as larvae and pupae samples. The insects found were used for PMI estimation. Following Diptera and Coleoptera species were found: Calliphora vicina, Calliphora vomitoria, Lucilia Caesar and Fannia sp. at different instars (from III to pupae), Necrodes sp., Dermestes sp., Necrobia sp., Creophilus sp. and Coleoptera Histeridae larva e and adults. Also species of Hymenoptera Formicidae, Hymenoptera parasites and mites were found. DNA typing was made using maggot crop and some of the arm bones compared with a bath sponge the man had used in the elderly residence. The DNA of crop contents couldn’t help us probably because of the high stage of decomposition of the body, but we could confirm that the cadaver was the missing man using bones and sponge samples. The colonization interval (C.I.) dated back to the beginning of March 2007. The toxicological exams on hair samples testified that the man was an habitual user of Delorazepam, but entomotoxicological exams showed the presence of Lorazepam in larvae and pupae. The presence of Lorazepam in the insect samples allowed us to assume that the man had taken this farmaceutical treatments shortly before dying. The death caused by benzodiazepine intoxication is a rare event and it is possible only if the condition of the body is compromised by other pathological situation, using anti-depressive medicine and alcohol. In this case, due to the condition of the corpse, it wasn’t possible to have information about the alcoholemy, but it could not be excluded. The body position in which the corpse was found and the presence of the drug allowed us to suppose that the man had died as a consequence of significant benzodiazepine intoxication happened before the death, characterized by an initial phase of lethargy, and followed by coma

Ocular swabs on exhumed bodies: An alternative to the collection of “classical” tissue samples in forensic genetics

We present the results obtained on DNA extracted from ocular (scleral/corneal) swabs collected from exhumed bodies at different times of burial. To our knowledge, there are no publications in the scientific forensic literature dealing with sclera/cornea as a source of DNA in the forensic laboratory. The obtained results demonstrate that cornea/sclera swabbing might be a promising alternative to the sampling of other tissues for DNA extraction even in highly putrefied bodies

Unusual Tissues and Sample Collection Strategies on Exhumed Bodies

The choice of soft or hard tissues to be sampled in case of exhumation of corpses for identification purposes or family relationship testing is based on the degradation conditions of the corpse: the more the corpse is degraded, the less DNA is expected to be retrieved from soft tissue. Therefore, the choice of the \u201cbest\u201d tissue samples usually falls on teeth and bones in these \u201cdifficult\u201d cases, even though the DNA extraction procedure requires time and effort and it can often result in unexpected, negative results. We here present the results of a daily practice survey that shows that it is possible to obtain good results even on DNA extracted from tissues that appear to be less \u201cappealing\u201d to the examiner by performing \u201csimple\u201d corneal/scleral swabs along with cartilage. While DNA extracted from cartilage has been already described, to our knowledge there is no evidence of publications in the scientific literature dealing with cornea/sclera as a source of DNA in the forensic laboratory. The obtained results demonstrate that it may be advisable to consider other tissues which bear the potential of returning good profile results despite not appearing particularly useful and better control of contamination

"Biological identikit": development of a SNPs-panel for the analysis of forensic DNA phenotyping and ancestry

The need to identify victims of mass disasters and perpetrators of crimes is fundamental for humanitarian, ethical and legal reasons. Individuals, whose genetic profiles are not yet known to investigators, cannot be identified by standard forensic DNA analysis. To date, technological progress allows for the analysis of Forensic DNA Phenotyping (FDP) which provides for the definition of Externally Visible Features (EVCs); and the analysis of the biogeographical ancestry (BGA), which allows to define the ancestral origin. The aim of this study was to evaluate the potential of a new panel of about 900 SNPs in predicting phenotypic traits and biogeographical origin. Recent biological material was analysed and subsequently the analysis was extended to include evidence found at the crime scene or extracted DNA, both preserved for long periods of time. The goal was to create a "biological identikit", useful for determining the phenotypic characteristics of unknown corpses and directing investigators to alleged victims or relatives or in a crime to narrow the circle of suspects. The panel consists of 41 SNPs for phenotyping and 850 SNPs for ancestry. It was tested on 8 recent samples and 26 samples extracted and stored for a long time. All the 891 SNPs were successfully incorporated into a single two-step multiplex PCR reaction using the IonAmpliSeq ™ Library Plus and applied for massive parallel sequencing with the Ion S5 platform using up to 0.05 ng / µl of DNA. The analysis of the results was carried out with an in-house predictive algorithm and by consulting 20 databases containing population frequencies. By comparing the results obtained with identikit or video-photographic surveys, it was possible to predict the phenotype and ancestry with an accuracy more than 90%. Although these new markers are unable to identify an individual, they can be a valuable investigative tool useful for personal identification

The instruments used by the Italian centres for cognitive disorders and dementia to diagnose mild cognitive impairment (MCI)

Aims: The purpose of this study was to examine the tools used in Italy to diagnose mild cognitive impairment (MCI). Methods: In collaboration with the Luigi Amaducci Research Consortium, the Italian Network of Alzheimer Evaluation Units prepared a questionnaire to describe how MCI is diagnosed in the Italian Centres for cognitive disorders and dementia (CCDD). Results: Most of the ninety-two CCDDs participating in the survey were located in hospitals (54.7%); large percentages were coordinated by neurologists (50.8%) and geriatricians (44.6%). Almost all (98.5%) used the Mini Mental State Examination to diagnose MCI; the Clock Drawing Test was also frequently used (83.9%). Other neuropsychological, imaging and biomarker tests were utilized less frequently and a wide diversity in the instruments used was noted. Conclusions: According to the results, diagnoses of MCI are based on a multitude of instruments, with major differences in the clinical assessment of geriatricians and neurologists. Standardized testing protocols, validated instruments and cut-off points need to be identified and adopted by the CCDDs for assessing MCI