Evaluation of blood, buccal swabs, and hair follicles for DNA profiling technique using STR markers

Evaluation of Maximum DNA Yield from a New Noninvasive Buccal Collection Device Following Various Extraction Protocols

Background: As the demand in genetic testing increases, various fields look toward collection methods that are noninvasive and efficient in recovering deoxyribonucleic acid (DNA) for testing that will allow for high first-pass success rates. Objective: Two extraction methods (PrepFiler™ Express Forensic Extraction and the Maxwell^® RSC Buccal Swab DNA Kits) were optimized to increase DNA yield from a buccal cell collection device (Gentueri's CollectEject™ Swab). Materials and Methods: Buccal swabs were processed under varying incubation parameters using a forensic workflow. The PrepFiler method was adjusted to test longer incubation times and more aggressive agitation. The Maxwell method was adjusted to test incubation temperatures and duration. Results: Quantitative results showed that increased agitation can yield more DNA through the PrepFiler extraction, but longer incubation times did not increase DNA recovery. The results from the Maxwell study showed no significant difference between incubation temperatures or times. Conclusions: The results indicate that various applied genetic fields can utilize a noninvasive, simple collection method using the CollectEject device in conjunction with extraction methods already implemented in laboratories to collect 5000 ng of DNA or greater from a buccal cell collection.

Chimeric status of biological samples after HSCT for personal identification: Y-STR based DNA analysis in sex mismatch cases

Identification of an individual is the prime object in forensic case works both in civil or criminal situations like paternity/maternity disputes, sexual assaults, murder, mass disaster victims etc. STR analysis has already proved its potential to give accurate results. In addition to autosomal chromosomes, sex determination at many times is crucial in forensic situations, especially in situations like rape cases or in cases of missing persons. The chances of wrong interpretations may arise due to false detection (or non-detection) of STR fragments overall or only at amelogenin-specific fragments, in situation like mutations, intersex conditions, trans-sexualism etc., due to natural or artificial chimersim. The forensic relevance of the possible misinterpretation of STR's or amelogenin should never be underestimated. The present study was carried out to identify an individual using Y-STR in sex mismatch patients who received hematopoietic stem cell transplantation. Hematopoietic stem cell transplantation is a method to replace patient's stem cell with the stem cell donated by the donor preferably biological related in order to cure malignant and non malignant diseases. This study enrolled ten female patients of HSCT. Samples were collected as pre and post transplant after 15 days, 30 days, 60 days, and 90 days of time interval from sex mismatch patient (female) and from donor (male) and chimeric status of the patient was analyzed using Y-STR markers (23 loci). Results demonstrated that donor genotype existed in blood and buccal swab of the recipient but no genetic profile existed for Y-STR in hair follicle of the recipient. This study suggests that only hair follicle out of three biological samples tested serves as reliable source of recipient's origin after HSCT for accurate personal identification especially in forensic situations.

Recent advances in genetic predisposition to pediatric acute lymphoblastic leukemia

Introduction: Historically, the majority of childhood cancers, including acute lymphoblastic leukemia (ALL), were not thought to have a hereditary basis. However, recent germline genomic studies have revealed that at least 5 - 10% of children with cancer (and approximately 3 - 4% of children with ALL) develop the disease due to an underlying genetic predisposition.Areas covered: This review discusses several recently identified ALL predisposing conditions and provides updates on other more well-established syndromes. It also covers topics related to the evaluation and management of children and family members at increased ALL risk.Expert opinion: Germline predisposition is gaining recognition as an important risk factor underlying the development of pediatric ALL. The challenge now lies in how best to capitalize on germline genetic information to improve ALL diagnosis, treatment, and perhaps even prevention.

Prepregnancy Genetic Carrier Screening in Recipients of Hematopoietic Stem Cell Transplants

BACKGROUND

Genetic carrier screening of individuals with a history of hematopoietic stem cell (HSC) transplant is not always straightforward.

CASE

We present the case of a couple who underwent prepregnancy genetic screening before fertility treatment. The genetics laboratory flagged the male partner's blood sample because there was a discrepancy between the sex of the patient and the sex chromosome markers, ultimately leading to the discovery of a prior HSC transplant.

CONCLUSION

A history of HSC transplant may confound results of serum-based genetic carrier screening. Hematopoietic stem cell transplant recipients are at risk for misinterpreted genetic carrier screening because the results of such screening may not actually be reflective of their own DNA.