Glossary

Adenovirus: family of viruses responsible for diseases such as cold, some conjunctivitis etc. Some adenovirus altered through genetic engineering are studied as vectors for gene therapy.

Aminoacid: organic molecule basic constituent of proteins. The sequence of amino acids is characteristic for each protein and determine the form of the protein.

Amniocentesis: removal of amniotic fluid; the analysis may lead early detection of abnormalities of the unborn. Usually it is performed between the sixteenth and the eighteenth week of pregnancy through a syringe.

Anabolism: phase of metabolism in which the substances introduced into the body "build" combinations of various types.

Anamnesis: collection of information relating to the events of health (medical history) of the patient and family. The genetic history is the careful examination of the relationship with the patient, generation to generation, considering the number of children, birth order, health and so on.

Apoptosis: term that indicates the "programmed cell death”, a normal physiological mechanism. Already in embryonic life, in fact, we have an excess of cells (for example neural) which are then removed through this delicate process to reach the "right" number. In diseases such as spinal muscular atrophy, the apoptosis is "disorderly" and there is a massive loss of motor neurons.

Asthenia: lack of strength, fatigue.

Asymptomatic: that presents no obvious signs of illness.

ATP: abbreviation of adenosin-triphosphate, a substance capable of delivering energy in the body.

Atrophy: failure to develop organs and tissues. The terms muscle atrophy and atrophic muscle mean the reduced volume of muscle.

Autosomal dominant: disease transmitted by the alteration of DNA represented in only one element of a pair of chromosomes. Hence it is sufficient that one of the parents suffers from the disease because it can occur in 50% of offspring. The risk of transmission is 50% for each pregnancy.

Autosomal recessive: the pathology that is expressed only when the alteration of DNA is present in both elements of a pair of chromosomes. It is necessary that there are two copies of the gene affected because the disease occurs. It follows that the two parents of a patient are carriers of the genetic defect, while not showing the disease. The risk of transmission of the disease is 25% for each pregnancy.

Autosomes: each of the non-sex chromosomes in the nucleus of a human cell.

Axon: nerve fiber, which is an extension of the motor neurons.

Biopsy: analysis that involves the removal of tissues or cells to be subjected to microscopic examination. The muscle biopsy is a sampling for diagnostic purposes of a piece of muscle. Treatment with different substances, reagents and colors of tissue taken (histological examination) may show abnormal microscopic details of muscle cells and their components, due to neuromuscular disorders.

Carnitine: substance partly taken with food, partly synthesized by the organism, which transports fatty acids of long chain to mitochondria for oxidation.

Carrier: the person who can transmit an infectious disease or inherited, without necessarily being himself sick. There is talk of asymptomatic carrier, when the subject has no clinical signs of disease, and carrier manifest when they are present.

Catabolism: is the set of metabolic pathways which break down molecules into smaller units and release energy.

Chromosomes: corpuscles present in the nucleus of the cell (they are 46, except that in the egg cell and sperm cell, where they are 23), of filamentous structure, arranged into 23 pairs and composed of a long chain of DNA, as well as a protein coating. Chromosomes contain the genes that carry the hereditary characteristics.

Chronic: that lasts over time.

Congenital: present from birth.

CPK: abbreviation for creatine phosphokinase (also known as creatine or, in acronym, CK), enzyme found typically in muscle and myocardium.

Creatine: amino acid present in muscle tissue.

Decubitus: literally the posture of a patient on the bed. Bedsores are lesions that can affect a patient due to compression suffering some support points of the body, usually where there are bony protrusions and where the pressure is concentrated (sacral region, beads, malleolus, etc.).

Deletion: the absence of substantial part of a gene.

DNA: abbreviation of deoxyribonucleic acid, organic macromolecule which contains all the genetic information.

Double-blind: expression that indicates a process that takes place in the trials of a treatment on humans, particularly in the phase III trials. Neither patients nor the doctors administering the treatment know if a person receives the drug or a placebo, a substance without intrinsic therapeutic value. This process is designed to minimize the importance of psychological factors in assessing the effectiveness of treatment.

Dysphagia: difficulty in swallowing.

Electromyography (EMG): technique that, taking advantage of electrodes applied to the muscle, has the purpose to highlight and record the electrical activity of voluntary muscle, whose changes may be a sign of neuromuscular disease.

Encode: action of a gene that provides the code, that is the instructions for making a protein.

Enzyme: protein with a key role in chemical reactions of the body, particularly in regulating their speed.

Etiology: the term indicates the study of the causes of a disease and the same causes.

Exon: stretch of DNA of a gene transcript (see Transcription).

Fasciculation: (or "muscle twitch") is a small, local, involuntary muscle contraction (twitching) visible under the skin arising from the spontaneous discharge of a bundle of skeletal muscle fibers. Fasciculations have a variety of causes, the majority of which are benign, but can also be due to disease of the motor neurons.

FDA: Food and Drug Administration (FDA) is an agency of the United States Department of Health and Human Services and is responsible for regulating and supervising the safety of foods, dietary supplements, drugs, vaccines, biological medical products, blood products, medical devices, radiation-emitting devices, veterinary products, and cosmetics.

Gene: stretch of DNA that contains a particular genetic information.

Gene product: what a particular gene produce (a protein).

Gene therapy: biomedical discipline that studies the possibility of transferring, for therapeutic purposes, a copy of healthy genes in diseased cells of patients suffering from genetic diseases. The principle is to use DNA as a drug and it can theoretically be used for other non-genetic diseases, such as for certain infections.

Genetic mutation: a change compared to normal and it is found in a segment of DNA that is part of a gene.

Genome: genetic content of a chromosome. The Genome Project is an international initiative aimed to identify all the genes, which are about 70,000.

Genotype: the system of genetic inheritance of an individual.

Heterozygote: leading the “character disease” only in one of two chromosomes inherited from parents.

Homozygous: leading both chromosomes of the parents with the same character (for example a "disease").

Hyposthenia: reduction of force.

Hypotrophy: term designating the lack of development of an organ or body part, such as a muscle.

Informed consent: form that patients must sign (or their parents or legal guardians in the case of minor subject) to participate in various stages of testing new therapies. In the form the limits of the trial, the possible risks and expected results are clearly explained. Patients may be subjected to the treatment (or intervention) only if they sign this agreement, but may stop completely free their participation in trials without having to account for their decision and without precluding the opportunity to undergo any other treatment.

Invasive: in the field of medical techniques, which involves the introduction into the body - through the skin or orifices - of instruments or foreign materials. With reference to the respiratory problems of neuromuscular patients, non-invasive ventilation is one that is practiced by the fan through the nose or mouth, while the-invasive ventilation is carried by tracheostomy.

In vitro: that takes place outside of a body, for example in cell cultures in the laboratory.

In vivo: that takes place directly in the body. So also is called a therapeutic approach in which the treatment is administered directly to the subject. The opposite approach is that ex vivo.

Locus: point of the chromosome where the gene resides.

Malignant hyperthermia: a complication of general anesthesia- rare but serious and potentially fatal - which occurs in people with a genetic abnormality of striped muscle fibers when they are exposed during anesthesia to special medication, (halogenated vapors and muscle relaxants), but theoretically this complication can occur with many other drugs.

Metabolism: it means all the physical and chemical processes in the body.

Mitochondria: organelles in the cell where chemical reactions occur for cell respiration and energy production. They have independent DNA.

Motor neurons: neurons located in the central nervous system that project their axons outside it and directly or indirectly control muscles.

mRNA: see RNA.

NAIP: abbreviation for Neuronal Apoptosis Inhibitory Protein, the name of one of the genes (another is the SMN) located on the long arm of chromosome 5 in the SMA region. The product of this gene is a protein that inhibits the neuronal apoptosis.

Neuromuscular: that interests the alpha-motor neurons of spinal cord, nerves, muscles and the point of junction between nerve and muscle. Under the definition of neuromuscular disorder we include both the diseases of the muscle (where muscle fibers are directly affected) and the affections of the nerves causing atrophy or other alterations.

Neuron: nerve cell.

Neurotransmitter: molecule that allows the transfer of signals between cells.

Nucleotide: sort of "brick" which comprises the structural unit of RNA and DNA.

Oligonucleotide: compound formed of few nucleotides.

Orphan drug: the term refers to a pharmaceutical product that has been developed specifically to treat a rare disease.

Petri plate (or Petri dish): it is a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells. The dish is named after the bacteriologist Julius Richard Petri, assistant to Robert Koch, who invented in 1877. Top plates have a diameter between 50 and 100 mm and a height of 15 mm.

Phenotype: all the physical characteristics of an individual, effect of genetic and environmental factors.

Physiopathology: discipline that studies the changes produced by the disease.

Physiotherapy: also known as physical therapy, rehabilitation is a practice that takes advantage of special exercises and massages and other physical media such as heat and cold, ultrasound, electricity, water (hydro) etc..

Placebo: inactive substance (without curative properties) that, in trials of a treatment in humans - particularly in the phase III trials, is administered to the patients without their knowledge, to use as a comparison and to limit the weight of the psychological factors in the evaluation of therapy: this process is called double-blind.

Point mutation: mutation in a gene consisting in an alteration of one or two bases at the most.

Progressive disease: disease whose symptoms gradually worsen over time.

Protein: organic molecule composed of amino acids that may have structural features, enzymatic or more.

Rare diseases: diseases that affect a few hundred, sometimes a few tens of people in the world and therefore are little studied.

Receptors: specialized structures - situated mainly on the surface of cells - which are used to receive signals of various types. Communication between signal and receptor determines the changes in the cell or in its functions.

Retrovirus: it is a virus with an RNA genome that replicates by using a viral reverse transcriptase enzyme to transcribe its RNA into DNA in the host cell. Some retroviruses modified by genetic engineering are studied as vectors for gene therapy.

RNA: abbreviation for ribonucleic acid. It is involved in the process of decoding the genetic instructions contained in DNA;mRNA is the acronym for the messenger RNA, the molecule that transfers information from genes to proteins.

SMA: acronym indicating the spinal muscular atrophy.

SMN: acronym for Survival Motor Neuron and the name of one of the genes whose alteration is implicated in spinal muscular atrophy and whose product is a protein important for the survival of motor neurons.

Splicing: it is the process of removing introns from immature RNA thus joining the exons. The exons are regions of the gene really coding, the introns do not encode. During the phase of transcription of protein synthesis the exons and introns are transcribed into a long strand of immature RNA. This filament is processed by spliceosomes, whose job is to cut off the chain the introns and reunite the exons, or coding areas. Some introns, defined self-splicing, are able to move out of the chain and reunite the two adjacent exons.

Stem cells: cells characterized by the ability to renew themselves and differentiating into a diverse range of specialized cell types.

Substitutions of bases: alteration of a particular stretch of DNA that affect the quality of the nucleotides that constitute it.

Synapses: zone of junction between nerve cells through which they "communicate". These include specialized vesicles filled with neurotransmitters, that is molecules that enable the transfer of signals between cells.

Tracheostomy: surgical procedure on the neck to open a direct airway through an incision in the trachea, allowing, for example in cases of neuromuscular diseases with respiratory complications, the application of equipment for ventilation.

Transcription: in genetics, the process by which RNA is synthesized by copying the DNA. The expression of genes in the cells begins with the creation of copies, or "transcripts" of the information contained in the gene, which are used by the cell to produce proteins.

Translocation: rearrangement due to the change of location of a chromosome segment.

Trial: in health care, clinical trials are conducted to allow safety and efficacy data to be collected for new drugs or devices, with a route that includes three phases: Phase I, with very low doses over a very small number of patients to determine its safety and review their mode of action; Phase II, where, with a small number of patients with different doses on different groups, it explored the effects and will seek guidance on appropriate doses and to see if the treatment merits further study; Phase III, where the drug is compared in double-blind with inactive drug (placebo) or with another drug standard, if available, on a number of patients that allows statistical evaluations. In all three phases the participants must sign a declaration of informed consent (signed by parents or guardians in the case of minor patients), without prejudice to the freedom to leave the experiments at any time without having to account for its decision.

Triplet: a set of three nucleotides (DNA fragments) that contains the genetic information for an amino acid.

Vector: in research on gene therapy is defined as any vehicle used to bring in a diseased cell healthy gene to replace the ill. There are viral vectors, which consist of virus manipulated through genetic engineering to contain therapeutic genes, and non-viral vectors, such as liposomes, synthetic vectors based on lipids.

X-linked: expression that defines a legacy in which the genetic defect is transmitted in the sex chromosome X.

Zygote: fertilized egg.

(sources: UILDM, Wikipedia)