Daniele Rodriguez

Deletion of amelogenin Y-locus in forensics: literature revision and description of a novel method for sex confirmation.

Today, the molecular technique routinely for sex determination in forensics is based the detection of length variations in the X-Y homologous amelogenin gene (AMELX and AMELY). In humans, the amelogenin gene is a single-copy gene located on Xp22.1-Xp22.3 and Yp11.2; the simultaneous detection of the X and Y alleles using polymerase chain reaction (PCR) can lead to gender determination. Several studies have shown that normal males may be typed as females with this test: AMELY deletions may result in no product of amplification and normal males being typed as female as a result of the test (negative male). Considering the consequences of the result obtained using only the amelogenin marker, and the related potential difficulties in interpreting the results, the gender misinterpretation may be troublesome in clinical practice and in forensic casework. In this article, beginning with a review of the incidence of gender-testing failures among different populations, and with the different strategies proposed in the literature in case of doubt regarding the presence of deleted AMEL in the DNA profile, we propose a method for the identification of samples with deleted AMEL that can be applied, as an additional assay, in case of doubt regarding PCR results of sex determination.

Effect of Dactyloscopic Powders on Dna Profiling From Enhanced Fingerprints: Results From an Experimental Study

AbstractWe conducted a study on the effect of fingerprint enhancement methods on subsequent short tandem repeat profiling. First, we performed a study typing blood traces deposited on 5 different surfaces, treated with 8 types of dactyloscopic powders. Three different DNA extraction methods were used. Subsequently, we analyzed latent fingerprints on the same 5 surfaces enhanced with the 8 different powders used in the first part of the study.This study has demonstrated that DNA profiling can be performed on fingerprints left on different substrates, and the substrate will affect the amount of DNA that can be recovered for DNA typing. In the first phase of the study, a profile was obtained in 92% of the 120 samples analyzed; in the second part, in 55% of the 80 samples analyzed, we obtained a profile complete in 32.5% of the cases. From the results obtained, it seems that the powders used in latent fingerprints enhancement, rather than having a direct inhibitory effect on extraction and amplification of DNA, may cause partial degradation of DNA, reducing the efficiency of amplification reaction. It should not be forgotten that these results were obtained under laboratory conditions, and in real caseworks, there may still be different problems involved.

Allele typing of short tandem repeats by capillary electrophoresis.

Abstract Capillary electrophoresis with laser-induced fluorescence was applied to the analysis of six STRs and the amelogenin sex test with the purpose of verifying accuracy and precision of the sizing method with the GS500 internal standard. Sequenced dye-labeled, PCR-amplified alleles from amelogenin, HumVWA31, HumTH01, HumF13A01, HumFIBRA, D21S11 and HumCSF1PO loci were run several times on the same capillary and on multiple capillaries and the offset of computer-measured fragment sizes from the expected molecular weights was calculated and analysed. All loci except D21S11 showed a poor degree of accuracy. Precision results from run-to-run and day-to-day injections displayed a maximum standard deviation (SD) > 0.15 nt for HumVWA31, HumF13A01, D21S11 and HumFIBRA, although the maximum range of calculated sizes in multiple runs was lower than 1 basepair. No variation in precision was observed according to the quality of the DNA template. Allele typing by comparison with allelic ladders for each locus is recommended.

Genetic Testing for Minors: Comparison between Italian and British Guidelines.

Genetic testing in children raises many important ethical, legal, and social issues. One of the main concerns is the ethically inappropriate genetic testing of minors. Various European countries established professional guidelines which reflect the different countries perspectives regarding the main ethical issues involved. In this paper, we analyze the Italian and the British guidelines by highlighting differences and similarities. We discuss presymptomatic, predictive, and carrier testing because we consider them to be the more ethically problematic types of genetic testing in minors. In our opinion, national guidelines should take into account the different needs in clinical practice. At the same time, in the case of genetic testing the national and supranational protection of minors could be strengthened by approving guidelines based on a common framework of principles and values. We suggest that the Oviedo Convention could represent an example of such a common framework or, at least, it could lead to articulate it.

Tumoural specimens for forensic purposes: comparison of genetic alterations in frozen and formalin-fixed paraffin-embedded tissues

In certain circumstances, tumour tissue specimens are the only DNA resource available for forensic DNA analysis. However, cancer tissues can show microsatellite instability and loss of heterozygosity which, if concerning the short tandem repeats (STRs) used in the forensic field, can cause misinterpretation of the results. Moreover, though formalin-fixed paraffin-embedded tissues (FFPET) represent a large resource for these analyses, the quality of the DNA obtained from this kind of specimen can be an important limit. In this study, we evaluated the use of tumoural tissue as biological material for the determination of genetic profiles in the forensic field, highlighting which STR polymorphisms are more susceptible to tumour genetic alterations and which of the analysed tumours show a higher genetic variability. The analyses were conducted on samples of the same tissues conserved in different storage conditions, to compare genetic profiles obtained by frozen tissues and formalin-fixed paraffin-embedded tissues. The importance of this study is due to the large number of specimens analysed (122), the large number of polymorphisms analysed for each specimen (39), and the possibility to compare, many years after storage, the same tissue frozen and formalin-fixed paraffin-embedded. In the comparison between the genetic profiles of frozen tumour tissues and FFPET, the same genetic alterations have been reported in both kinds of specimens. However, FFPET showed new alterations. We conclude that the use of FFPET requires greater attention than frozen tissues in the results interpretation and great care in both pre-extraction and extraction processes.

The Eluana Englaro Case: Cause of death after the withdrawal of artificial nutrition and hydration in a subject in a permanent vegetative state and with quadriplegia

A 38-year-old woman, who had been in a permanent vegetative state with quadriplegia for 17 years following a motor vehicle accident, died 87 h after the judicially authorised suspension of artificial nutrition and hydration. Medico-legal investigations, requested by the Judicial Authorities and focusing on the evaluation of clinical and necroscopic data, aimed to explain the cause of death, to exclude any lethal cause other than one deriving from the withdrawal of artificial nutrition and hydration and to verify the level of perceived discomfort and the correctness in the application of the supportive protocol during the end of life phase. The inability of quadriplegic patients to compensate critical hyperthermic and haemodynamic disturbances induced by dehydration was considered to be the cause of a rapid demise after the withdrawal of artificial sustenance.

Diffuse pulmonary ossification in permanent vegetative state

Diffuse pulmonary ossification (DPO) is a rare condition characterized by diffuse metaplastic bone formation in the lungs. Two patterns have been described: dendriform, with a coral‐like network of bone spiculae along the alveolar septa; and nodular, with lobulated fragments in the alveolar spaces. Dendriform DPO is frequently associated with chronic pulmonary pathologies. We present here the first case of DPO associated with a long‐lasting vegetative state. Micro‐computed tomography (MicroCT) was applied to analyze the distribution of pulmonary ossification in volumes of lung samples. It showed a mean volume percentage of ossification of 0.79% and 3‐D reconstructions permitted to reveal the branching pattern and internal cavities of some ossifications. The occurrence of DPO in a persistent vegetative state (PVS) may be favored by recurrent pulmonary infections, due to aspiration and immunological defects, and respiratory instability, due to brain damage and the fact of being bedridden. Fibrotic reactions probably represent a preliminary step in bone formation. Further studies could examine the incidence and clinical significance of DPO in subjects in PVS or patients who are bedridden for other reasons. MicroCT may facilitate analysis of more case histories, with greater sensitivity with respect to classic microscopic analyses.

Delayed diagnosis of Wernicke encephalopathy with irreversible neural damage after subtotal gastrectomy for gastric cancer: A case of medical liability?

Highlights • This case report concerns Wernicke’s encefalopathy occurring in cancer gastrectomy.• WE is often under-diagnosed and under-treated in gastric cancer patients.• Other etiologies of WE should be excluded, in order to avoid claims of medical malpractice, which can cause enormous professional and economic costs.• Monitoring for WE has yet to be recommended in the clinical guidelines.• Specific guidelines on possible side effects of necessary surgery are needed.

Disabling Outcomes After Peripheral Vascular Catheter Insertion in a Newborn Patient: A Case of Medical Liability?

Patient: Female, newborn Final Diagnosis: Loss of falange of the hand Symptoms: Manual disability • Pain Medication: Ampicilline Clinical Procedure: Insert vascular catheter Specialty: Forenscic Medicine Objective: Rare disease Background: The positioning of peripheral venous catheters (PVC) is an invasive procedure commonly performed in pediatrics hospital wards to obtain vascular access for the administration of fluids, medications and other intravenous (IV) therapies. Many studies exist about management of peripheral venous access in adults. On the contrary, scientific evidence on the management of this procedure in children and newborns, especially regarding the optimal duration of infusion and the possible related side effects, is still poor. To minimize the risk of phlebitis, the guidelines of the US Centers for Disease Control and Prevention suggest the replacement of the catheter every 72–96 hours in adult patients, while in pediatric patients the catheter can remain in place for the entire duration of the IV therapy, unless complications arise. Case Report: In the presented case, after the positioning of a PVC in a newborn, no clear signs/symptoms of phlebitis were registered before the sixth day and, despite the immediate removal of the catheter, the thrombotic process, secondary to phlebitis, was already occurring, causing serious and permanent disabling outcomes, susceptible to legal medical evaluation and financial compensation. Conclusions: The knowledge of this case is particularly interesting to clinicians working in the field of neonatal care and to clinical risk management services inside hospital structures, since similar cases may be the source of requests for extremely high financial compensations due to medical liability.

An unusual case of chronic cough: Professional liability in dentistry?

Foreign body aspiration (FBA) is a serious medical problem, also in dental practice. The case report describes the case of a patient who for 12 years has suffered from chronic cough as a result of the aspiration of a polymeric silicone resin fragment during a dental procedure. In November 2002, the patient was underwent dental care, and she points out that, when performing dental imprint, she had sensed that something “went down in the throat” but she was immediately reassured by the dentist. After lung CT was performed, the foreign body was identified and removed with benefit to the patient. The knowledge of this case report could be useful for dentists who perform dental impressions, to be aware of the fact that the material used is radiolucent e.g. cannot be seen on plan radiographs and it can be accidentally inhaled by the patient. The knowledge of the case is also important for doctors who come in contact with patients who previously underwent dental treatment, suffering from persistent cough, in the absence of positive radiological signs.