Late-onset Disorders

Late-onset Disorders include adult diseases such as Alzheimer’s, Huntington's and heart disease. One of the uses of PGD are the identification of embryos at risk for late-onset diseases. Late-onset Disorders are complex and have both genetic and environmental causes. Genetic tests may indicate a susceptibility or predisposition for these diseases. Diseases like Huntington's disease, are caused by single genes that also are seen later in life. These types of disorders can be tested for at any time.

Preimplantation genetic diagnosis (PGD) technology allows genetic testing of human eggs and embryos before pregnancy making it completely realistic to establish only potentially normal pregnancies without Alzheimer's disease or any other late-onset disorder with a genetic predisposition. With no current prospect for the treatment of Alzheimer's disease, prevention of an inherited predisposition to Alzheimer's is the only option for couples at risk.

Treatment:

Recently through studying blood samples of families in which there is a history of late-onset diseases like breast cancer, scientists have isolated and identified a gene linked to breast cancer. In families with hereditary breast cancer, which accounts for less than ten percent of all cases, mutations in the BRCA1 gene confer an 85% lifetime risk of the disease, as well as a 45% chance of ovarian cancer. Some women in such families who have learned that they carry a mutated BRCA1 have elected to undergo Prophylactic mastectomy and oophorectomy (removal of the ovaries), a procedure that may reduce but does not eliminate the risk of cancer. PGD was performed for some couples with late-onset disorders. This involved a standard IVF protocol, allowing oocytes or embryos to be tested prior to their transfer back to uterus. Maternal mutation was tested by sequential PCR analysis of the first and second polar bodies, removed following maturation and fertilization of oocytes, while paternal mutation analysis required embryo biopsy at the cleavage stage. To avoid misdiagnosis due to allele drop out, multiplex nested PCR was applied, involving p53 mutation analysis simultaneously with the linked short tandem repeats in intron 1.

Treatment Value:

By being able to identify these genes through particular "markers" associated with the gene, doctors will know which individuals are more susceptible to late-onset disorders. The extremely difficult life experience of families affected by inherited Alzheimer's disease or any other catastrophic late-onset disorder--being unable to help their family members suffering from the disease and being afraid they will soon develop the disease themselves--makes them responsible for insuring that their children will not face the same difficulties.

Next Steps:

If you think you have a Genetic Disorder your next step should be:

• Obtain a Free e-Mail Consultation
• Arrange a Telephone Consultation
• Arrange an office Consultation