Preimplantation genetic diagnosis for hereditary cancers

Simple and Easy to Perform Preimplantation Genetic Diagnosis for β-thalassemia Major Using Combination of Conventional and Fluorescent Polymerase Chain Reaction

BACKGROUND

Thalassemias are the most common monogenic disorders in many countries throughout the world. The best practice to control the prevalence of the disease is prenatal diagnosis (PND) services. Extensive practicing of PND proved effective in reducing new cases but on the other side of this success high abortion rate is hided, which ethically unfair and for many couples, especially with a previous experience of a therapeutic abortion, or moral concerns, is not a suitable choice. Preimplantation genetic diagnosis (PGD) is a strong alternative to conventional PND. At present PGD is the only abortion free fetal diagnostic process. Considering the fact that there are more than 6000 single gene disorders affecting approximately 1 in 300 live-births, the medical need for PGD services is significant.

MATERIALS AND METHODS

In the present study development of a PGD protocol for a thalassemia trait couple using nested multiplex fluorescent polymerase chain reaction (PCR) for the combination of polymorphic linked short tandem repeat (STR) markers and thalassemia mutations is described. Restriction fragment length polymorphism used to discriminate between wild and mutated alleles.

RESULTS

In PGD clinical cycle, paternal and maternal alleles for D11S988 and D11S1338 STR markers were segregated as it was expected. PCR product for IVSII-1 mutation was subsequently digested with BtscI restriction enzyme to differentiate normal allele from the mutant allele. The mother's mutation, being a comparatively large deletion, was detectable through size differences on agarose gel.

CONCLUSION

The optimized single cell protocol developed and evaluated in this study is a feasible approach for preimplantation diagnosis of β-thalassemia in our patients.

Comparison of attitudes regarding preimplantation genetic diagnosis among patients with hereditary cancer syndromes

Preimplantation genetic diagnosis (PGD) allows couples to avoid having a child with an inherited condition, potentially reducing cancer burden in families with a hereditary cancer predisposition. This study investigated and compared awareness and acceptance of PGD among patients with different hereditary cancer syndromes. Questionnaires were mailed to 984 adults with hereditary breast and ovarian cancer, Lynch syndrome, familial adenomatous polyposis, or multiple endocrine neoplasia type 1 or 2. Associations between clinical, demographic, and psychosocial factors and awareness and acceptance of PGD were examined. Of 370 respondents (38 % return rate), 28 % felt their syndrome impacted family planning, 24 % were aware of PGD, 72 % felt that PGD should be offered, 43 % would consider using PGD, and 29 % were uncertain. Family experience and syndrome-specific characteristics, such as disease severity, quality of life and availability of medical interventions as well as gender, family planning stage, and religiosity impact perceptions of the acceptability of PGD, though a high level of uncertainty exists. Hereditary cancer patients lack awareness of PGD despite feeling that PGD should be offered, highlighting the need for education on this topic. While we found attitudes about the acceptability of PGD to be generally similar to those reported in the literature and of genetics and ethics experts, we observed similarities and differences between syndromes that provide insight into why some hereditary cancer patients may find PGD more acceptable than others.

Fertility issues in cancer survivorship

Breakthroughs in cancer diagnosis and treatment have led to dramatic improvements in survival and the need to focus on survivorship issues. Chemotherapy and radiotherapy can be gonadotoxic, resulting in impaired fertility. Techniques to help cancer survivors reproduce have been improving over the past decade. Discussion of the changes to a patient's reproductive health after cancer treatment is essential to providing comprehensive quality care. The purpose of this review is to aid in pre- and posttreatment counseling, focusing on fertility preservation and other strategies that may mitigate risks to the patient's reproductive, sexual, and overall health.