Page 90 - Ethical Guidelines for Conducting Research Studies Involving Human Subjects

means that asymptomatic blood relatives can have the genetic test that would
look for the specific mutation. Specific issues include consent and family
communication and dynamics.

❑ Karyotyping: Karyotyping is used as a tool for the etiological diagnosis of
patients with mental retardation (MR) and birth defects. A precise diagnosis may
lead to prevention or even an earlier detection of some pathogenic signs (e.g.
obesity in Prader–Willi patients, Wilms tumor in Wilms tumor, aniridia,
genitourinary anomalies mental retardation (WAGR) syndrome) or may enable
improved medical care for the individual (e.g. echocardiogram if a gene implicated
in congenital heart disease is involved). Moreover, a diagnosis often is essential
for genetic counseling and reproductive choices of the individual and his/her
family.

The consequences of DNA testing for conditions for which no treatment is
available or for conditions manifesting late in life e.g. breast cancer, Alzheimer’s
disease etc. should be seriously considered before embarking on such studies.
Information so derived should not disclose the identity of the individuals.

ANNEXURE – B

Gene therapy is the use of DNA as a pharmaceutical agent to treat disease. It
derives its name from the idea that DNA can be used to supplement or
alter genes within an individual's cells as a therapy to treat disease. The most
common form of gene therapy involves using DNA that encodes a functional,
therapeutic gene to replace a mutated gene. Other forms involve directly
correcting a mutation, or using DNA that encodes a therapeutic protein drug
(rather than a natural human gene) to provide treatment. In gene therapy, DNA
that encodes a therapeutic protein is packaged within a "vector", which is used to
get the DNA inside cells within the body. Once inside, the DNA becomes
expressed by the cell machinery, resulting in the production of therapeutic
protein, which in turn treats the patient's disease.

Types of gene therapy:

Gene therapy may be classified into the two following types:

1) Germ line gene therapy

2) Somatic gene therapy
1) Germ line gene therapy

In germ line gene therapy, germ cells (sperm or eggs), are modified by the
introduction of functional genes, which are integrated into their genomes. Germ
cells will combine to form a zygote which will divide to produce all the other cells
in an organism and therefore if a germ cell is genetically modified then all the
cells in the organism will contain the modified gene. This would allow the therapy
to be heritable and passed on to later generations. Although this should, in

BMRC ETHICAL GUIDELINE ON HUMAN SUBJECTS Page 86