Genome decoded, now Parsi ills can be tackled

Parsis are known to be prone to cancer. Soon, we may know what causes it.

For the first time, scientists have sequenced the entire genome of a Parsi woman (74) suffering from an heritable form of breast cancer.

Researchers say, the exercise will help in finding variations in DNA. Once matched with DNA of other communities, they will know if these changes in DNA are unique to Parsis and are associated with the disease.

The finding will lead to proper diagnosis and help the Parsis — a fast depleting community — not to be susceptible to it.

The exercise is a part of "Avestagenome Project" — a study on the Parsis to determine the genetic basis of their longevity and age-related disorders.

Speaking to TOI, Dr Sami Guzder, head of science and innovation division at Avesthagen — a Bangalore-based biotechnology company — said, "we will know in two months that variations is possibly causing this spike in breast cancer cases among the Parsis."

The incidence of breast cancer in most communities is strongly linked to a genetic cause, but currently little is known about the variants. By employing whole-genome sequencing of affected individuals, all genetic variants linked to the disease can be identified. "This will lead to a broader understanding of breast cancer disease mechanisms, the development of new diagnostic tests and the discovery of new drug targets and design of drugs," Dr Guzder explained.

He added, "we will medically analyse the genome and compare them with that of normal healthy population. The variations in DNA will be substantiated through a larger study among 1,000 Parsis. Validation studies will show if the variants are constantly found in specially breast cancer patients. We will be able to identify predictive biomarkers to pinpoint what’s causing these cancer cases among the Parsis." Dr Guzder has over 4,000 blood samples collected from Parsis in eight cities. The whole genome sequencing was carried out in partnership with The Genome Analysis Centre (TGAC), UK.

The Parsis are a distinct minority population with unique traits, including longevity, but also suffer from predispositions to certain diseases like breast cancer.