Page 87 - Ethical Guidelines for Conducting Research Studies Involving Human Subjects

ANNEXURE - A

Genes which code for a protein, enzyme, or a transporter in a particular
individual, and to find out if there is any mutation, single nucleotide
polymorphism, or copy number variations, RNAi, introns and exons etc which
may determine the susceptibility of the individual to a disease or the response to
drugs.

Single Nucleotide Polymorphism (SNP)

SNP genotyping is the measurement of genetic variations of single nucleotide
polymorphisms (SNPs) between members of a species. It is a form of genotyping,
which is the measurement of more general genetic variation. SNPs are one of the
most common types of genetic variation. A SNP is a single base pair mutation at a
specific locus, usually consisting of two alleles (where the rare allele frequency is
>1%). SNPs are found to be involved in the etiology of many human diseases like
cancer, infectious diseases (AIDS, leprosy, hepatitis, etc.) autoimmune,
neuropsychiatric, Sickle–cell anemia, β Thalassemia and Cystic fibrosis and are
becoming of particular interest in pharmacogenetics. SNPs are usually biallelic
and thus easily assayed. A single SNP may cause a Mendelian disease. For
complex diseases, SNPs do not usually function individually; rather, they work in
coordination with other SNPs to manifest a disease condition as has been seen in
Osteoporosis.
In studies on human genetic polymorphisms, such as single nucleotide
polymorphisms (SNPs), little immediate benefit is expected for the individuals
contributing the test samples. Such lack of immediate benefits should be noted in
the informed consent form obtained prior to sample collection.

Mutation

In genetics, a mutation is a change of the nucleotide sequence of the genome of an
organism, virus, or extra chromosomal genetic element. Mutations result from
unrepaired damage to DNA or to RNA genomes (typically caused by radiation or
chemical mutagens), from errors in the process of replication, or from the
insertion or deletion of segments of DNA by mobile genetic elements. Mutations
may or may not produce discernible changes in the observable characteristics
(phenotype) of an organism. Mutations play a part in both normal and abnormal
biological processes, including evolution, cancer, and the development of the
immune system.

There are a number of diseases caused by mutation in human genome e.g. Sickle-
cell disease, Hemophilia, Cystic fibrosis, Down syndrome, Duchenne muscular
dystrophy etc.

Although mutations that change in protein sequences can be harmful to an
organism; on occasions, the effect may be positive in a given environment. In this
case, the mutation may enable the mutant organism to withstand particular
environmental stresses better than wild-type organisms, or reproduce more

BMRC ETHICAL GUIDELINE ON HUMAN SUBJECTS Page 83