Molecular genetics unit

View interesting links

The Umbert Institute has a genetics unit split into clinical and molecular areas.

Clinical genetics
Like other medical specialties, clinical genetics is based on clinical examination and additional complementary tests to obtain a precise diagnosis of possible genetic diseases that the patient may have.

It is important to reach a diagnosis as this will make it possible to:

· Provide knowledge of the disease and any possible complications, and the possibility to prevent these
· Investigate the possible causes
· Provide personalised genetic advice
· Prevent these diseases being passed on to later generations and risk recurrence
· Provide the greatest support to patients and their families by giving them information on mutual help groups and associations

Skin disorders are often one further manifestation of a broader clinical manifestation affecting other parts of the body. That is why it is important to perform a multidisciplinary examination of the patient, and the dermatologist that identifies the skin lesion must work with a team of different specialists that includes the clinical geneticist.

During the genetic consultation, the patient will be asked about personal and family pathological history to identify any possible hereditary pathologies, and a careful examination made of the skin as well as other organs that could help in the diagnosis.

We will also weigh up the possibility of additional diagnostic tests as well as possible available genetic studies for the pathology affecting the patient. The idea is to make an overall assessment of the patient and reach a diagnosis, which will then make it possible to have an in-depth knowledge of the pathology affecting the patient, how far the disease has spread, and to establish an appropriate follow-up to head off any possible associated problems that may emerge. It will also make it possible to gauge the risk for the patient and identify at-risk family members by offering genetic advice tailored to the patient.

Molecular genetics

The majority of organisms -mammals included- are formed by eukaryotic cells, i.e. cells that store all genetic information within the cell core.

The chromosome is the largest hereditary transmission unit and it consists of densely packed deoxyribonucleic acid (DNA). The human body has 23 pairs of chromosomes.

The functional units of the chromosomes are called genes and they make for the smallest existing unit of hereditary information. Each chromosome consists of thousands of genes, each one of them carrying the necessary information to perform the synthesis of a protein or protein subunit -- a vital process for the proper formation, development and growth of our organism.

DNA molecules can undergo changes in both its structure and composition. These changes are called mutations. A less formal use of this word normally refers to DNA sequence alterations affecting protein function. A disease-related mutation refers to a DNA sequence alteration that either alters or destroys the protein's proper function thus causing a disease or increasing the level of predisposition towards it.

In the case of dermatology, the agent causing a higher damage on DNA composition is sun exposition (ultraviolet radiation).

Genes related to cancer predisposition include the following:
1.- Tumour-suppressing genes
2.- Oncogenes
3.- DNA-damage response genes

Tumour-suppressing genes and oncogenes tend to act concertedly to adjust growth and cell division in such a way that proteic products of tumour-suppressing genes inhibit growth while those of oncogenes promote it.

While the existance of two copies of tumour-suppressing genes may intensify cell proliferation, one single oncogene copy can cause an uncontrolled cell growth even with normal tumour-suppressing genes.

Tumour-suppressing genes are those involved in family cancer syndromes. In order to develop cancer both gen copies need to be altered. That is, for a person to develop cancer he/she needs to have inherited not only one altered gene copy but two.

This concept is extremely important when trying to put an end to the false idea that cancer is inherited from one generation to the next. Individuals don't inherit cancer but a higher susceptibility to develop it.

Thus it is extremely important to perform a genetic consultation in order to evaluate the existing possibilities of developing a neoplasm. Instituto Umbert includes in its structure the genetics unit so as to offer an appropriate advising service to clients with skin cancer antecedents or any other neoplasms such as colon cancer, stomach cancer or breast cancer, amongst others.

Genetics Units :

•  Genetics and Cancer : sporadic, familial and hereditary
•  Genetics and Anti-Aging

Genetics and Cancer

Cancer is a usual disease, since it is estimated that 1 out of 3 people of the general population would develop some type of cancer throughout their lives. It specially appears in old people, as a result of genetic alterations produced during the life span of the individual (sporadic cancer) or as a result of susceptibility genetic factors that are present in that person since the time of conception (familial and hereditary cancer, and also sporadic cancer). The genetic alterations responsible for sporadic cancer are ussually the result of environmental factors, among others. In dermatology, the most important environmental factor causing genetic alterations is sun exposure (ultraviolet rays)

Late identification of several genes predisposing to some types of cancer has opened the possibility of offering some specialized, genetic advice to individuals and families having family records of cancer. Identification of those individuals and families having a higher risk of developing cancer helps us to advice some prevention strategies and early diagnosis, as well as a personal evaluation of the risk for developing cancer. It should be taken into consideration that cancer is not inherited, but the predisposition or genetic susceptibility to develop it. Moreover, inheriting a genetic susceptibility to cancer does not directly mean you are going to develop neoplasia, but the risk of developing it is higher than that for the general population for that specific type of cancer.

The objective of the cancer consultation is to advice those patients having family records for skin cancer and other neoplasies, such as colon, endometrial, breast, ovary and stomach cancer, among others. But also those individuals with predisposing phenotypic characteristics and environmental factors.

Genetics and Anti-Aging

Preventive, predictive and personalized medicine:

•  Preventive genetic profiles: man and woman, basic and complete.
•  Nutrigenetic profile.
•  Pharmacogenetic profile.
•  Personal analysis of other genetic polymorphisms.

Medicine has always dealt with curing or improving diseases: that is Curative or Palliative Medicine. Nowadays, however, preventive medicine is more important, that is, the group of actions and medical advices directed to promote health and disease prevention.

We all have a minimum risk of developing a particular disease: that's the population risk. But there are some individuals who show a higher probability to develop a disease. This may be because of both environmental or lifestyle factors, as well as susceptibility or predisposition genetic factors. Therefore, some people show a priori a higher risk of developing a disease than the population risk; that is, they have genetic susceptibility or predisposition to a specific pathology. Predictive medicine consists on the analysis and recognising of our own genetic susceptibility.

Preventive genetic profiles evaluate the probability or risk of each person to develop those diseases usual during adulthood. It is estimated that 91% of the population would show, throughout their life, a genetic disease and that 65% would develop one of the usual diseases of adulthood; such as; diabetes mellitus, obesity, arterial hypertension, hypercholesterolemia, breast and prostate cancer, senile dementia and osteoporosis.

Diet is the most important environmental factor. We all know, however, that there is not a healthy diet for everyone. A diet being healthy for one person would be that adapted to its genetic profile: its nutrigenetic profile . Therefore, the main aim for Nutrigenetics is a personalized diet, that is, the perfect diet for each person according to his/her genes. There is food having a protective action for some specific diseases, while other would cause the opposite effect according to each individual's nutrigenetic profile. Therefore, the nutrigenetic profile analysis helps us to know what food increase or decrease the risk of developing some diseases in a particular individual. So, nutrigenetics' aim is to prevent diseases by means of nutrition. A nutrigenetic profile-based nutrition is the best elixir of good health and the best remedy for any disease.

It is supposed that 1 out of 3 patients do not respond to the pharmacologic therapies according the preset mode, although the medication, the type of administration and the dose were adequate to diagnosis. An efficient and secure dose of a medicine for a patient could be inefficient or toxic for another patient on similar conditions. Many times, such variations are the result of genetic differences on genes codifying proteins related to the medicine's action. Such a high percentage of failure is not acceptable; especially in those cases we do have the methods to prevent them. The aim of the pharmacologic profile is the individual therapy, that is, know what medicines and what doses are more adequate for each patient.

We are what we decide to be (what we do, what we eat, what we drink, etc.), but also what we do not decide ourselves (our genes). To know our genes, our genetic susceptibility, is to have the possibility to decide on those traits already given at birth. To know our genetic susceptibility to adult-frequent diseases makes it possible to take preventive actions against them to avoid them from appearing or, in case they develop, to help the prognostic to be the best and the severity to be lowest. Predicting those diseases for which the individual shows a higher risk (genetic susceptibility) is essential for their prevention.

We cannot change our genes, but we can change their effect on our health by changing our lifestyle. Preventing is ok, but it would be better if we knew what to prevent and to do it, predicting is necessary.

On Preventive Medicine, the sooner we take healthy factors or lifestyles and preventive-medicine advices, the sooner we would notice their effects on our health and would avoid, as much as possible, the development of those diseases for we could have a higher genetic susceptibility.

Preventive genetic profiles are specially recommended from 40 years old on, although the best age is 30. At these ages, knowing our genetic susceptibility helps to take preventive actions. From 50 years old on, knowing our genetic susceptibility has lower effects on prevention, but continues to be really important on choosing the most suitable treatment for each individual.

The nutrigenetic profile is recommended at any age, although the sooner we adapt the diet to our genes, the sooner we would notice the benefits on our health. Therefore, it is better for a person to know its nutrigenetic profile from 20-30 years old. The pharmacogenetic profile is also good to take it from 20-30 years old on.