Screening the gene

While the concept of genetic testing is not entirely new in the Philippines, there is an unfamiliarity among Filipinos regarding its availability, accessibility, and relevance here in the country.

 

Genetic testing is a type of medical test that identifies changes in chromosomes, genes or proteins. According to Dr. Carmencita Padilla, executive director of the Philippine Genome Center, genetic testing cannot stand alone, and is in fact part of a bigger picture called genetic services or the activities for the diagnosis, care, and prevention of genetic diseases.

In an interview with BusinessWorld, Dr. Padilla said the results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder.

“Say I have three generations of women with breast cancer: my mother, my aunt, and my grandmother. How does genetic testing help me? Through genetic testing, it is possible to look for a marker linked to cancer that is common to the three of them. If I happen to have the marker, I can conduct the necessary screening and undergo regular testing earlier, compared to other relatives who do not have the marker,” she explained.

More than 1,000 genetic tests are currently in use, she added, and more are being developed.

Several methods can be used for genetic testing, including molecular genetic tests or “gene tests,” in which single genes or short lengths of deoxyribonucleic acid (DNA) are studied to identify variations or mutations that lead to a genetic disorder; chromosomal genetic tests, in which whole chromosomes or long lengths of DNA are analyzed to see if there are large genetic changes �” such as an extra copy of a chromosome �” that can cause a genetic condition; and biochemical genetic tests, in which the amount or activity level of proteins are studied, and abnormalities found in either can indicate changes to the DNA that result in a genetic disorder.

Chromosomal studies are available in only three institutions, namely the National Institutes of Health (NIH), University of the Philippines�“Manila; St. Luke’s Medical Center; and the National Kidney and Transplant Institute, while biochemical testing is available exclusively at the NIH. Molecular testing for some conditions, on the other hand, is available in some institutions, but most are on a research basis.

For Dr. Padilla, these tests are available in the Philippines only “in a limited sense,” primarily because the tests require special equipment and specially trained staff.

She explained that chromosomal and biochemical testing are not free, and the cost of the tests may be deemed expensive by an ordinary Filipino family. “Only NIH provides a charity rate for indigent patients,” she said.

On the other hand, since most of molecular testing is done for the purpose of research, the service is free to patients.

Newborn screening �” a procedure usually covered by PhilHealth which screens a newborn for a select number of metabolic conditions �” is the only population-based testing that is available in all hospitals in the country. Dr. Padilla said it is important for this procedure to be available and accessible to all Filipinos because certain conditions or diseases may still be treated.

“Prompt treatment can reverse the complications like mental retardation or death,” she said.

She noted, however, that other genetic tests should be done only if the patient really needs them. Typically, a geneticist assists in deciding what additional tests are needed, and when genetic tests are done, it is recommended that the patient goes through pre- and post-testing genetic counseling.

“Even a normal result has many implications. It is unfortunate that we have only nine geneticists in the country to serve 90 million people,” Dr. Padilla said.

According to her, the country needs more students and educators to take a special interest in genetics and genomics.

“The next generation of students must realize that these fields are important for the country. Worldwide now, there is a pool of geneticists and genomic experts in every country to study conditions that are of special interest in the population. We need this ‘pool’ also in the Philippines,” she concluded.

source:  Businessworld