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Next-Generation Sequencing 139

per year (Penchaszadeh, 2013). It is estimated that the private sector would
have done the same amount of studies. These included the most common
genetic diseases: cystic fibrosis, spinal muscular atrophy, fragile X syndrome,
13
Duchenne and Becker muscular dystrophy, Prader Willi syndrome , achon-
14
droplasia and, hypochondroplasia, Steinert myotonic dystrophy, Friedreich’s
ataxia, etc.) To date, there is no data available about the frequency of studies
that are carried out in the adult population, either for genetic or oncological
diseases.

NEXT-GENERATION SEQUENCING

Patricia dreamed of having children. Her mother had died of breast cancer
when she was a child, and her maternal aunt has battled against breast cancer
for years. Her geneticist advised her on the possibility of studying her aunt
to find out if she had a mutation in any of the 19 genes that are now associ-
ated with hereditary breast and/or ovarian cancer. If her aunt was a carrier,
they would confirm the suspicion that her family was transmitting hereditary
breast cancer, and then Patricia would be studied. After performing the studies,
a mutation was found in her aunt. It was then found that Patricia had inher-
ited the genetic mutation that placed her within a women group with a high
chance of being exposed to breast cancer. She was about to decide not to have
children when she felt that perhaps she was dragging her husband into making
the wrong decision. They consulted a specialist who proposed to them that
they undergo an embryonic selection treatment. Mutation-free embryos would
be implanted in her uterus. The couple accepted the proposal. Patricia gave
birth to two girls free of this mutation. Today Patricia does not think about
the future. She is calm, because she knows that her daughters can grow to be
healthy women and mothers who will see their children grow up and—why
not?—their grandchildren, too.
The Human Genome Project, which began in 1990, required 11 years of work
to achieve a complete human genome sequence, 20 research groups from dif-
ferent countries that worked together, and billions of dollars.
15
Since the appearance of next-generation sequencing (NGS) in the market, it
has been possible to sequence up to 100 human genomes in less than 2 weeks,
and at a cost lower than US$1000.

This has not only caused a revolution in genetic testing, but is also chang-
ing the form of research in medicine, giving the possibility of knowing the

13 A Neurological inherited disorder.
14 Defective conversion of cartilage into bone, especially at the epiphyzes of long bones,
producing a type of dwarfism.
15 NGS also known as high-throughput sequencing, is the catch-all term used to describe a
number of different modern sequencing technologies.