Human Genetics: The New Panacea?

AuthorDiane Longley,Julian Kinderlerer
DOIhttp://doi.org/10.1111/1468-2230.00170
Published date01 September 1998
Date01 September 1998
Human Genetics: The New Panacea?
Julian Kinderlerer and Diane Longley*
Considerable advances have been made in human genetics in recent years, often
outstripping the knowledge and understanding of the medical professions as well
as the general public and taking regulators by surprise. In this paper, we seek to
give a realistic indication of the many developments in human genetics and of what
might or might not be scientifically possible in time, without the clutter and
sensationalism of media hype. This, we feel, is an essential exercise to enable
certain key elements and concerns to be taken on board, putting developments in
context prior to any fresh consideration of the need for and potential effectiveness
of regulation of human genetics.
The elucidation of the structure of DNA during the 1950s1provided a model for
understanding the process for the transfer of genetic information between
generations of the same organism. In bacteria and fungi identification of a variety
of enzymes capable of modifying this group of large molecules has made possible
the science termed ‘modern biotechnology’, and opened up our understanding of
the mechanisms which lead from information molecule to function. Until the
identification of these new enzymes scientists had used a variety of mutagenic
devices (including, for example, ultra-violet light) to modify the genetic
information in bacteria and fungi and observe the change in characteristics (or
phenotype). From the late 1970s it became possible both to insert and remove
genes in bacteria and to observe the consequences. An understanding of the control
mechanisms followed rapidly. It became possible to sequence and extract genes
from higher organisms and insert them into bacteria. Numerous quantities of the
bacteria could then be grown, which meant that the amount of both the gene and
the protein derived from that gene was relatively large, allowing analysis.
In 1990 a fateful decision was made. The entire human genome was to be
sequenced. A ‘genome’ is the complete set of genes and chromosomes of an
organism.2The intention was to construct a ‘high-resolution genetic, physical and
transcript map’ of the human, with ultimately, a complete sequence. The Human
Genome Project is the largest research project ever undertaken with the intention of
analysing the structure of human DNA and determining the location of the
estimated 100,000 human genes. According to Hieter and Boguski:
The information generated by the human genome project is expected to be the source book
for biomedical science in the 21st century and will be of immense benefit to the field of
medicine. It will help us to understand and eventually treat many of the more than 4000
genetic diseases that afflict mankind, as well as the many multi-factorial diseases in which
genetic predisposition plays an important role.3
About 40,000–50,000 genes have been identified, although for a majority the
The Modern Law Review Limited 1998 (MLR 61:5, September). Published by Blackwell Publishers,
108 Cowley Road, Oxford OX4 1JF and 350 Main Street, Malden, MA 02148, USA. 603
* Sheffield Institute of Biotechnological Law and Ethics.
1 J.D.Watson and F.H.C. Crick, ‘A Structure for Deoxy-ribose Nucleic Acid’ (1953) 171 Nature 737.
2 P. Hieter and M Boguski, ‘Functional Genomics: It’s All How You Read It’ (1997) 278 Science 601.
3Human Genome News (1998)9,1–2. http://www.ornl.gov/TechResources/HumanGenome/project/
project.html.
function is still unknown.4Whilst more than 95 per cent of the human genome
remains to be sequenced, the acceleration in the process as new techniques are
introduced means that the 15 year timescale originally envisaged for the completed
project is likely to be met.5
It should be pointed out that a complete sequence does not provide information
that allows an understanding of the mass of data. It can (to some extent) be
compared to the possession of a very large encyclopaedia written in an unknown
language. The complete sequence will not be ‘sufficient to understand its
functional organisation, neither for individual units nor at a more integrated level’.6
The emphasis will quickly shift from the huge databases that store the recorded
information to a functional analysis. It is assumed that there are about 100,000
genes with specific functions in the genome. The function of most of these is
unknown. ‘In the past we have had functions in search of sequence. In the future,
pathology and physiology will become ‘‘functionators’’ for the sequences’.7
DNA profiling and similar techniques show very clearly that (virtually) no two
individuals share the same genome. There will be differences in many of the genes on
their chromosomes. Whose genome is, therefore, being sequenced? Sequences are not
being determined for an individual, but rather for the genetic information of a large
range of persons. This has resulted in an appreciation of the ‘polymorphism’ in our
genetic make-up. Many of the amino-acids found in the linear sequence of a protein
cannot be changed, for the change is likely to have a deleterious impact on the
function. As proteins are directly coded in the DNA, there must be a similar constraint
on the DNA. Many of the proteins found in humans are also found in other organisms.
Even though the function is the same or similar, their sequence differs significantly.
Hence exact replication is unnecessary. The DNA sequence that makes up many genes
will differ from organism to organism, and even from person to person.
8
Duboule9raises the question that lies at the heart of this article. How will it be
possible to assimilate the mass of newly available information and translate it into
clinical practice ‘in a way that fulfils scientific criteria and respects ethical as well
as social concerns’?
Genetic and biological advances
For obvious reasons, development of modern biotechnology proceeded apace in
bacteria, viruses and fungi much earlier than in higher organisms. Within bacteria,
fungi and plants it is now possible to move almost any ‘gene’10, from any one
4 L. Rowen, G. Mahairas and L. Hood, ‘Sequencing the Human Genome’ (1997) 278 Science 605 and
Schuler et al ‘A Gene Map of the Human Genome’ (1996) 274 Science 540–546.
5 S.E. Koonin, ‘An Independent Perspective on the Human Genome Project’ (1998) 279 Science 36.
6 D. Duboule, ‘The Evolution of Genomics.’ (1998) 278 Science 555.
7 D. Tosteson, Symposium on ‘Genomics and Gene Therapy: Meaning for the Future of Science and
Medicine’ (1997) Harvard Institute of Human Genetics, Cambridge MA 26 March 1997: cited in P.
Hieter and M. Boguski, n 2 above.
8 D. Wang et al ‘Large Scale Identification, Mapping and Genotyping of Single-Nucleotide
Polymorphisms in the Human Genome’ (1998) 280 Science 1077.
9 See n 6 above.
10
Gene is defined as ‘The fundamental physical and functional unit of heredity. A gene is an ordered
sequence of nucleotides located in a particular position on a particular chromosome that encodes a
specific functional product (i.e., a protein or RNA molecule).’ Gene expression is defined as ‘The process
by which a gene’s coded information is converted into the structures present and operating in the cell.
Expressed genes include those that are transcribed into mRNA and then translated into protein and those
that are transcribed into RNA but not translated into protein (e.g., transfer and ribosomal RNAs).’ The
definitions are taken from A Primer on Molecular Genetics (1992) US Department of Energy, Office of
Energy Research, Office of Health and Environmental Research, Washington, 36.
The Modern Law Review [Vol. 61
604 The Modern Law Review Limited 1998

To continue reading

Request your trial

VLEX uses login cookies to provide you with a better browsing experience. If you click on 'Accept' or continue browsing this site we consider that you accept our cookie policy. ACCEPT