Glossary of terms

Routes that allow a medicine to be approved early, with less data, for serious diseases when there is no adequate treatment. In the US, the FDA calls this accelerated approval; in Europe, the EMA grants a conditional marketing authorisation. The company must carry out further studies to confirm the medicine's benefit. In the US, if the benefit is not confirmed, the approval can be withdrawn.

Source: FDA – Accelerated Approval · EMA – Conditional marketing authorisation

Amniocentesis is the taking of a sample, with a thin needle, from the fluid that surrounds the baby during pregnancy. This fluid is used to look for certain genetic conditions in the baby. It is usually done between weeks 15 and 20 of pregnancy. There is a small risk of miscarriage, and the decision belongs to the family.

Source: NHS – Amniocentesis

An antisense oligonucleotide is a short piece of DNA or RNA made in the laboratory. It sticks to a specific RNA in the cell. In this way, it changes whether that RNA makes protein, or alters its other functions. New treatments for some diseases are being researched in this way.

Source: NCI Dictionary of Cancer Terms – antisense oligonucleotide · NHGRI Talking Glossary – Antisense

One changed copy of the gene is enough to cause the disease. This copy can come from the mother or the father. An affected parent has a 1 in 2 chance of passing it to each child. Sometimes the change is new and appears in someone with no affected relatives.

Source: NHGRI Talking Glossary – Autosomal Dominant Disorder · MedlinePlus Genetics – What are the different ways a genetic condition can be inherited?

Both copies of the gene must be changed for the disease to occur. One copy comes from the mother and one from the father. If both parents are carriers, in each pregnancy the chance that the child is affected is 1 in 4. These diseases are more likely in marriages between relatives.

Source: NHGRI Talking Glossary – Autosomal Recessive Disorder · HSGM – Evlilik Öncesi SMA Taşıyıcı Tarama Programı · HSGM – Evlilik Öncesi Hemoglobinopati Tarama Programı

Breathing support means helping a person who has trouble breathing with a machine. The machine pushes air into the lungs. If the air is given through a face mask, this is called non-invasive (NIV) support; in severe cases, a breathing tube may be needed. In long-term illness, it can also be used at home if the family is trained.

Source: NHLBI – What Is a Ventilator?

A person who has a disease-causing change in one copy of a gene but is not ill. A carrier can pass this change on to their child. This matters in recessive and X-linked diseases. If both parents are carriers of the same disease, the child is at risk of having it.

Source: NHGRI Talking Glossary – Carrier · MedlinePlus Genetics – What are the different ways a genetic condition can be inherited?

This test looks at small pieces of DNA in the pregnant woman’s blood. Some of these pieces come from the placenta and are very similar to the baby’s DNA. It carries no risk for the baby, but it is a screening test and does not give a definite diagnosis. If the result shows a high risk, further tests are needed for a definite diagnosis.

Source: MedlinePlus Genetics – What is noninvasive prenatal testing (NIPT)? · NHGRI Talking Glossary – Cell-Free DNA Testing

A test during pregnancy that looks for a genetic or chromosome condition in the baby. A small piece is taken from the placenta (afterbirth). It is usually done between weeks 11 and 14 of pregnancy. There is a small risk of miscarriage; the family decides whether to have it.

Source: NHS – Chorionic villus sampling

A chromosomal microarray is a test that examines DNA on a chip. It can find small pieces that are missing or extra in a chromosome. These pieces may be too small to be seen on a karyotype. However, it usually cannot see gene changes at the level of a single letter.

Source: NHGRI Talking Glossary – Microarray Technology · NHS Genomics Education Programme – Microarray · NHGRI Talking Glossary – Copy Number Variation (CNV)

Chromosomes are thread-like structures in the nucleus of a cell. DNA is tightly wound up inside these structures. Humans have 23 pairs, that is, 46 chromosomes. In each pair, one comes from the mother and one from the father.

Source: NHGRI Talking Glossary – Chromosome · MedlinePlus Genetics – What is a chromosome?

Research that tests how well a new treatment works in people and how safe it is. The new treatment is often compared with an existing treatment or with a placebo. A participant can leave the trial at any time without their care being affected. In Türkiye, trials of medicines and medical devices are authorised by TİTCK.

Source: MedlinePlus – Clinical Trials · NHS – Clinical trials · TİTCK – Görev Alanları

Keeping vaccines and some medicines at a certain temperature from production to use. Medicines stored in the refrigerator are usually kept between 2 and 8 °C. If the temperature is not maintained, the medicine may lose its effect; if the power goes out, you can ask a pharmacist.

Source: CDC Pink Book – Chapter 5: Vaccine Storage and Handling · NHS United Lincolnshire Hospitals – Storing medicines at home

A consanguineous marriage is a marriage between people who share a common ancestor; most often it is between cousins. It is common in many parts of the world, including Türkiye. Because the partners may carry the same recessive gene change, the risk of diseases with recessive inheritance increases. Genetic counseling can help a family understand its own risk.

Source: Oniya O ve ark. Akraba evliliğinin üreme sonuçları: derleme. Eur J Obstet Gynecol Reprod Biol 2019 (PubMed 30502592) · Hiz Kurul S ve ark. Türkiye'de akraba evliliği olan ailelerde trio ekzom. Brain 2022 (PubMed 34791078)

Corticosteroids are medicine forms of certain hormones that the body makes itself. They reduce inflammation and swelling and suppress an overactive immune response. With long-term or high-dose use, side effects may increase. After long-term use, the medicine should not be stopped suddenly without talking to a doctor.

Source: NHS – Steroids · NCI Dictionary of Cancer Terms – corticosteroid

A device that helps people who cannot cough well because of muscle weakness to clear mucus. It first pushes air into the lungs, then quickly pulls it back out; this imitates a cough. It is used with a mask, a mouthpiece or through a tracheostomy.

Source: Cochrane – Mechanical insufflation-exsufflation for people with neuromuscular disorders

A report prepared by a medical board for children under 18. It shows the child's special needs. Instead of a disability percentage, the report states the level of special need. The report alone does not grant rights; each institution applies its own conditions.

Source: Çocuklar İçin Özel Gereksinim Değerlendirmesi Hakkında Yönetmelik (mevzuat.gov.tr)

A de novo change is a gene change found in the child but not in the mother or the father. It arises by chance in the egg or sperm cell, or just after fertilization. It may be the cause of a condition never before seen in the family. It is usually not related to anything the parents did.

Source: MedlinePlus Genetics – What is a gene variant and how do variants occur? · NHS Genomics Education Programme – De novo variant

Giving food and fluids through a tube into the stomach or small intestine. It is used for people who cannot eat enough, or safely, by mouth. The tube can pass through the nose or be placed through the abdomen into the stomach.

Source: NHS Rotherham Doncaster and South Humber – Enteral nutrition · MedlinePlus – Nutritional Support · SGK – Sağlık Uygulama Tebliği, md. 4.2.8.A (mevzuat.gov.tr)

A treatment that gives, as a medicine, an enzyme the body lacks. It is used in some inherited metabolic diseases. The medicine is given into a vein, often for life. Its effect on signs that involve the brain is usually limited.

Source: MedlinePlus Genetics – How are genetic conditions treated or managed? · Coutinho MF ve ark. Less Is More: Substrate Reduction Therapy for Lysosomal Storage Disorders. Int J Mol Sci. 2016 (hakemli derleme, PMC)

Whether a person with a medical condition can travel safely by plane. If oxygen or a device is needed on board, the airline is told in advance. A medical information form (MEDIF) filled in by the doctor may be requested; the airline makes the final decision.

Source: UK Civil Aviation Authority – Assessing fitness to fly · CDC Yellow Book – Air Travel

A gastrostomy is a feeding tube placed through the skin of the abdomen directly into the stomach. It is used in people who have difficulty swallowing or cannot get enough nutrition by mouth. It may also be considered when food often goes down into the windpipe. The tube may be short-term or permanent.

Source: MedlinePlus – Feeding tube insertion – gastrostomy

A gene is the basic unit of heredity and is made of DNA. Genes pass from parents to children. Many genes carry the instructions for proteins the body needs to work. Humans have about 20,000 genes that make proteins.

Source: MedlinePlus Genetics – What is a gene? · NHGRI Talking Glossary – Gene

Methods used to change DNA at a specific point. The best known is CRISPR-Cas9. Base and prime editing make small changes without cutting both strands of DNA. How safe and effective these methods are in humans is still being studied for many diseases.

Source: MedlinePlus Genetics – What are genome editing and CRISPR-Cas9? · NHGRI Talking Glossary – CRISPR · NIBIB (NIH) – Scientists unveil search-and-replace genome editing · Matsoukas IG. Prime Editing: Genome Editing for Rare Genetic Diseases Without Double-Strand Breaks or Donor DNA. Front Genet. 2020

A gene panel is a test that looks at several genes at the same time. The genes on the panel are chosen from those that could cause the person’s symptoms. It is useful when the symptoms fit several conditions. A change in a gene that is not on the panel will not be seen with this test.

Source: MedlinePlus Genetics – What are the different types of genetic tests? · NHS Genomics Education Programme – Panel testing

A treatment that aims to correct the genetic problem behind a disease. For example, a working copy of a faulty gene is given to the cells. It is in use for a small number of diseases. Many gene therapies are still being studied to see whether they are safe and effective.

Source: MedlinePlus Genetics – What is gene therapy? · FDA – What is Gene Therapy?

A permanent change in the DNA sequence. It used to be called a mutation. Today the word variant is used more often, because not every change causes disease. Some variants lead to disease, but many have no effect on health.

Source: MedlinePlus Genetics – What is a gene variant and how do variants occur? · NHGRI Talking Glossary – Mutation · NHGRI Talking Glossary – Genomic Variation

Information about genetic diseases given to a person or family by a health professional trained in this field. How the disease might affect the family and the risks are discussed. Test results are explained. The aim is to help the family make informed decisions and cope with the situation.

Source: NHGRI Talking Glossary – Genetic Counseling · MedlinePlus Genetics – What is a genetic consultation?

A medical test that looks for changes in genes or chromosomes. The result can confirm or rule out a diagnosis. Exome sequencing reads the parts of genes that make proteins; this is about 1 percent of the DNA. Genome sequencing looks at all of the DNA.

Source: MedlinePlus Genetics – What is genetic testing? · MedlinePlus Genetics – What are whole exome sequencing and whole genome sequencing? · NHS – Genetic and genomic testing

An institution of the Millî Eğitim Bakanlığı (Ministry of National Education) that handles guidance and special education. There, a board assesses whether a child needs special education. The parent or the school can apply.

Source: MEB – Özel Eğitim Hizmetleri Yönetmeliği, md. 4 (z) ve md. 7 (mevzuat.gov.tr)

Medical care given at home to people who are bedbound, dependent on a device or homebound because of a diagnosed disease. The Ministry of Health provides this service. You can apply through e-Nabız or by calling the Ministry’s contact center; hospital websites give the number as 444 38 33.

Source: Evde Sağlık ve Palyatif Bakım Hizmetlerinin Sunumu ve Koordinasyonuna İlişkin Yönetmelik, md. 4 ve 6 (Resmî Gazete, 23.6.2026, sayı 33289) · Sağlık Bakanlığı – Evde Sağlık Hizmetleri İletişim Merkezi 444 38 33

A breathing machine that can be used at home to move air into and out of the lungs. It can be used for people who need long-term breathing support and whose condition is stable. Caregivers need to be trained.

Source: NHLBI (NIH) – Ventilator/Ventilator Support · SGK – Sağlık Uygulama Tebliği, md. 3.3.6 (mevzuat.gov.tr)

The international classification the World Health Organization uses to code diseases. ICD-11 is the latest version, in effect since 1 January 2022. It includes about 5,500 rare diseases. All of these diseases have an identification number, but only some have their own separate code.

Source: WHO – International Classification of Diseases (ICD) · WHO – Frequently asked questions: Rare diseases (ICD)

A child with special educational needs studying in the same class or school as their peers. The child may be with peers all day, or may take lessons in a special education class for part of the day. Meanwhile, support education is provided to the child and the teacher.

Source: MEB – Özel Eğitim Hizmetleri Yönetmeliği, md. 4 (ö) (mevzuat.gov.tr) · MEB – Ortaöğretim Kurumları Yönetmeliği, md. 4 (i) (mevzuat.gov.tr)

A written education plan prepared for a student with special educational needs. The child’s development, needs and situation at school are taken into account. The plan sets out the goals to be reached and the support education to be provided.

Source: MEB – Özel Eğitim Hizmetleri Yönetmeliği, md. 4 (g) ve (ff) (mevzuat.gov.tr)

A disease caused by a change in the genes. This change often comes from the mother or the father. Sometimes it appears for the first time in the family, in the child. An inherited change is found in almost every cell of the body.

Source: MedlinePlus Genetics – What is a gene variant and how do variants occur? · MedlinePlus – Genetic Disorders

An antibody that the body of some people with haemophilia makes against the clotting factor. An inhibitor reduces or removes the effect of the factor medicine given. As a result, treatment works less well. The haemophilia team plans another treatment for these people.

Source: NHS – Haemophilia · MedlinePlus Medical Encyclopedia – Hemophilia A

A karyotype is the complete set of a person’s chromosomes. The name is also used for the laboratory test that arranges the chromosomes in order and shows them. The test looks for large changes in the number or structure of the chromosomes. It cannot see small gene changes.

Source: NHGRI Talking Glossary – Karyotype · NHS Genomics Education Programme – Karyotyping · MedlinePlus Genetics – What are the different types of genetic tests?

A report issued by a board of several specialist doctors instead of a single doctor. It is issued at authorised hospitals. For people aged 18 and over, the disability report is issued this way and the degree of disability is written as a percentage. This report may be required for SGK payment of some medicines and for many rights.

Source: Erişkinler İçin Engellilik Değerlendirmesi Hakkında Yönetmelik (mevzuat.gov.tr) · SGK Sağlık Uygulama Tebliği (SUT), madde 4.1 ve 4.3 (mevzuat.gov.tr)

A food made for the special nutritional needs of a disease and used under medical supervision. It can be given by mouth or by tube. For example, it provides the vitamins and minerals that a person on a restricted diet cannot get from food.

Source: FDA – Medical Foods Guidance Documents & Regulatory Information · MedlinePlus – Phenylketonuria · SGK – Sağlık Uygulama Tebliği, md. 4.2.8.A (mevzuat.gov.tr)

A document issued by a doctor that is needed for SGK to pay for certain medicines. The report states the diagnosis and the active ingredient of the medicine; sometimes the dose and duration are also included. It is issued by a specialist or a health board and is renewed when it expires.

Source: SGK – Sağlık Uygulama Tebliği, md. 4.1.3 ve 4.1.8 (mevzuat.gov.tr)

A sudden worsening in a person with an inborn metabolic disease. Fever, long fasting, vomiting or diarrhea can trigger it. That is why the doctor often provides a written emergency plan in advance.

Source: Rossi ve ark. (2021), J Inherit Metab Dis – A generic emergency protocol for patients with inborn errors of metabolism causing fasting intolerance (PMC) · MedlinePlus Genetics – Maple syrup urine disease

In some inborn metabolic diseases, the body cannot process a certain substance in food. A special diet that reduces this substance is the main part of treatment. The diet is tailored to the person, monitored with frequent blood tests and is often lifelong.

Source: NICHD (NIH) – What are common treatments for phenylketonuria (PKU)? · MedlinePlus – Phenylketonuria

Mitochondria are small structures that produce energy in the cell, and they carry their own DNA. A baby receives mitochondria only from the mother, through the egg cell. So a change in mitochondrial DNA passes from the mother to the child, not from the father. The condition can affect both daughters and sons.

Source: MedlinePlus Genetics – What are the different ways a genetic condition can be inherited? · NHGRI Talking Glossary – Mitochondrial DNA

A monoclonal antibody is a protein made in the laboratory. It is designed to attach to a single target in the body. It is used in the diagnosis and treatment of many diseases. Its effects and side effects depend on the target.

Source: NCI Dictionary of Cancer Terms – monoclonal antibody

In mosaicism, some of the cells in the body have a different genetic makeup. This difference arises after fertilization, at an early or late stage of development. Depending on which cells have the change, the symptoms may be mild or severe. Mosaicism does not always cause disease.

Source: NHGRI Talking Glossary – Mosaicism · NHS Genomics Education Programme – Mosaicism

Some diseases are caused not by a single gene but by the combined effect of many genes and the environment. Diet, physical activity or harmful substances in the environment also play a role. These diseases may be common in a family, but they do not follow a specific inheritance pattern. This is why the risk is hard to calculate.

Source: MedlinePlus Genetics – What are complex or multifactorial disorders? · NHGRI Talking Glossary – Complex Disease

A thin tube that goes in through the nose and down the esophagus to the stomach. Food and medicines are given into the stomach through this tube. It is usually used for short-term feeding.

Source: MedlinePlus – Nasogastric feeding tube

A screening test done with a few drops of blood from the baby's heel. The aim is to find some diseases early and start treatment early. In Türkiye, six diseases are screened; SMA was added in 2022. Screening does not make a diagnosis; a baby with a suspicious result is referred for further tests.

Source: HSGM – Yenidoğan Tarama Programı · MedlinePlus – Newborn Screening

Occupational therapy helps a person who has difficulty doing everyday tasks. It looks at activities such as getting dressed, eating, school or work. For a task that is difficult, another way of doing it or an assistive device is sought. It can be done with people of all ages at home, at school or at work.

Source: NHS – Occupational therapy

Using a medicine outside its approved use (indication) in Türkiye. Some uses on the TİTCK list do not need extra approval. For other uses, TİTCK approval is needed before use, and the application is made by the doctor treating the patient. The approval is valid only for that patient.

Source: TİTCK – Endikasyon Dışı İlaç Kullanımı Kılavuzu (sayfa ve ekler) · TİTCK – Endikasyon Dışı İlaç Kullanımı Kılavuzu (PDF)

A unique number that Orphanet gives to each rare disease. Orphanet is an international source of information on rare diseases. This code helps doctors and researchers in different countries know they are talking about the same disease. ORPHA codes are matched with other coding systems such as ICD.

Source: Orphanet – About Orphanet

An official status given to a medicine developed to diagnose, prevent or treat a rare disease. This status gives the company developing the medicine some incentives. Orphan status does not mean the medicine is approved or that it works. To be approved, the medicine goes through scientific assessment like any other medicine.

Source: EMA – Orphan designation: overview · FDA – Designating an Orphan Product: Drugs and Biological Products · Orphanet – What is an orphan drug?

A support device worn on the outside of a part of the body. It helps prevent or correct a deformity and improve function. Splints, corsets, special shoes and insoles are examples of orthoses.

Source: NHS Wirral University Teaching Hospital – What is orthotics? · SGK – Sağlık Uygulama Tebliği, md. 3.1.1 ve 3.1.2 (ortez ve protezler) (mevzuat.gov.tr)

An electrically powered device that produces oxygen from the air for oxygen therapy at home. It does not need refilling. A backup oxygen cylinder is kept in case of power outages; the device should be kept away from open flames and cigarettes.

Source: MedlinePlus – Using oxygen at home · NHS – Home oxygen treatment · SGK – Sağlık Uygulama Tebliği, md. 3.3.6 ve 3.3.6.B (mevzuat.gov.tr)

Palliative care aims to improve the quality of life of a person with a serious, long-lasting illness. Pain and other distressing symptoms are eased. Emotional, social and spiritual support is also given, and the family is included in this support. It can be given not only at the end of life but from diagnosis onward, alongside other treatments.

Source: WHO – Palliative care (fact sheet) · NHS – What end of life care involves

A study is checked by other experts in the same field before it is published in a journal. This review helps find mistakes and improve quality. Drafts that have not been peer reviewed are called preprints. Results in a preprint may change later.

Source: Kelly J ve ark. Peer Review in Scientific Publications: Benefits, Critiques, & A Survival Guide. EJIFCC. 2014 (PMC) · PubMed Central (NLM) – NIH Preprint Pilot: What is a preprint?

Penetrance describes what proportion of people who carry the same gene change develop symptoms of the disease. If some of those who carry it never have symptoms, this is called reduced penetrance. The reason may be other genes, the environment and lifestyle. This makes it harder to estimate the risk within a family.

Source: MedlinePlus Genetics – What are reduced penetrance and variable expressivity? · NHS Genomics Education Programme – Penetrance

In phase 1, a medicine is tried for the first time in a small number of people; safety and dose are studied. In phase 2, effects and side effects are watched in more people who have the disease. In phase 3, the medicine is compared with an existing treatment or a placebo in large groups. Phase 4 takes place after the medicine is approved; safety and effects continue to be monitored.

Source: FDA – Step 3: Clinical Research · NHS – Clinical trials

A phenotype is all the traits of a person that can be seen or measured. Height, eye color or blood group are examples. In a disease, the signs and symptoms make up the phenotype. The phenotype is shaped by both genes and the environment.

Source: NHGRI Talking Glossary – Phenotype · NHGRI Talking Glossary – Genotype

Physiotherapy aims to make movement easier and reduce pain in illness or disability. Exercise, massage and other methods are used. Muscle strength, balance and breathing can also be worked on. People of all ages, including children, can have physiotherapy.

Source: NHS – Physiotherapy

Something that looks like the real treatment but contains no active substance. It is used in clinical trials to understand the real effect of a new treatment. One group gets the new treatment, the other gets the placebo, and the results are compared. In most trials, people do not know who is in which group; this is called blinding.

Source: NHS – Clinical trials

During IVF treatment, embryos are genetically tested before they are placed in the womb. The aim is to avoid passing on to the child a serious genetic condition already known in the family. This is why IVF is needed even if the couple has no fertility problem. The test is not completely accurate.

Source: HFEA – Pre-implantation genetic testing (PGT-M and PGT-SR)

Blood tests for couples who go to their family doctor for the marriage health report. They check carrier status for inherited blood diseases such as thalassaemia and sickle cell anaemia. SMA carrier status is also screened. If both partners are carriers, genetic counselling is recommended.

Source: HSGM – Evlilik Öncesi Hemoglobinopati Tarama Programı · HSGM – Evlilik Öncesi SMA Taşıyıcı Tarama Programı

Treatment given to prevent a problem before it happens. For example, in severe haemophilia, regular injections are given to prevent bleeding. Treatment given only when a problem starts is called on-demand treatment.

Source: NHS – Haemophilia

A clinical trial in which people are put into groups by lot, that is, by chance. One group gets the new treatment. The control group gets the standard treatment or a placebo. Thanks to the random draw, the groups are similar and the treatments are compared more fairly.

Source: NHS – Clinical trials · FDA – Step 3: Clinical Research

A disease that affects a small number of people. In Europe, a disease is considered rare if it affects fewer than 5 in 10,000 people. Some rare diseases are genetic; for others, the cause is not yet known. Most are serious and long-lasting.

Source: Orphanet – About rare diseases · EMA – Orphan designation: overview · FDA – Rare Diseases at FDA

Payment of the cost of a medicine or treatment by SGK, Türkiye's Social Security Institution. The rules are set out in the Health Implementation Communiqué (Sağlık Uygulama Tebliği, SUT). Medicines that SGK pays for are on the Reimbursed Medicines List (Bedeli Ödenecek İlaçlar Listesi, EK-4/A). Some medicines are paid for only with a medical report; there are separate rules for medicines brought from abroad.

Source: SGK Sağlık Uygulama Tebliği (SUT), madde 4.1 ve 4.3 (mevzuat.gov.tr) · SGK – Yurt dışından ilaç temini

Having the diagnosis or treatment plan reviewed by another doctor as well. A second opinion may confirm the first doctor’s recommendation or offer other options. Asking for a second opinion is the patient’s right; it helps to bring your medical records with you.

Source: MedlinePlus – Your cancer diagnosis: do you need a second opinion?

A secondary finding is a result of a genetic test that has nothing to do with what was originally being looked for. For example, an increased risk of another disease may be seen. This information sometimes helps with taking early action. Before the test, you may be asked whether you want to learn about results of this kind.

Source: NHGRI Talking Glossary – Secondary Genomic Finding · MedlinePlus Genetics – What are secondary findings from genetic testing?

siRNA is a small piece of RNA made in the laboratory. It finds the message of a disease-causing gene inside the cell and makes it inactive. This is called gene silencing. Treatments that work this way are being used or researched for some genetic diseases.

Source: Ebenezer O ve ark. Recent Update on siRNA Therapeutics. Int J Mol Sci 2025 (PubMed 40331977)

Traveling to another country for stem cell procedures whose effectiveness and safety have not been proven. Harms such as blindness, tumors and serious infections have been reported with these procedures. Caution is needed with stem cell treatments offered for payment outside clinical trials.

Source: FDA – Important Patient and Consumer Information About Regenerative Medicine Therapies · Jawad ve ark. (2012), Br J Gen Pract – Safeguarding patients against stem cell tourism (PMC)

Healthy stem cells are given to replace damaged blood cells. Stem cells are found in the bone marrow and in the blood. The patient's own cells or a donor's cells are used. It is used in some blood and immune diseases; recovery can take up to a year.

Source: NHS – What is a stem cell or bone marrow transplant? · NHS – Why a stem cell or bone marrow transplant is done

A type of treatment used in some storage diseases. It does not replace the missing enzyme. Instead, it makes the cell produce less of the substance that builds up. Some of the medicines used for this are taken by mouth.

Source: Coutinho MF ve ark. Less Is More: Substrate Reduction Therapy for Lysosomal Storage Disorders. Int J Mol Sci. 2016 (hakemli derleme, PMC)

A device that suctions mucus from the mouth, the throat or a tracheostomy tube. A thin, soft tube is attached to the device. Family members can learn from the health team how to do this at home.

Source: MedlinePlus – Tracheostomy care

A room within the school set up for students studying through inclusion. The student gets extra support here in the subjects they need. This support is given alongside classroom teaching, not instead of it.

Source: MEB – Özel Eğitim Hizmetleri Yönetmeliği, md. 4 (i) (mevzuat.gov.tr) · MEB – Ortaöğretim Kurumları Yönetmeliği, md. 4 (cc) (mevzuat.gov.tr)

A syndrome is a picture made up of signs and symptoms that often occur together. This combination helps to recognize a particular condition. Some syndromes are genetic. For others, the cause is not known.

Source: NHGRI Talking Glossary – Syndrome

The Turkish Medicines and Medical Devices Agency is an agency of the Ministry of Health. It licenses medicines and medical devices and inspects products on the market. It authorises clinical trials. It also gives approval for matters such as off-label use and bringing medicines from abroad.

Source: TİTCK – Görev Alanları · TİTCK – Tarihçe · TİTCK – Yurt Dışından İlaç Temini ve Kullanımı Kılavuzu

An opening made into the windpipe at the front of the neck. A tube is placed through this opening. The tube is used to help breathing, to remove mucus from the lungs or to connect a breathing machine.

Source: NHS – Tracheostomy · MedlinePlus – Tracheostomy

Transition is a young person’s planned move from a pediatrician to an adult doctor. The aim is for the young person to learn to manage their own health and for care to continue without a break. Preparation usually starts around age 12–14. The plan is made together with the young person and their family.

Source: Got Transition – Six Core Elements of Health Care Transition

Treatment that cannot be done in Türkiye being carried out abroad with SGK (Social Security Institution) coverage. This requires a health board report from a public tertiary-care hospital. The report is verified by designated hospitals and approved by the Ministry of Health.

Source: 5510 sayılı Sosyal Sigortalar ve Genel Sağlık Sigortası Kanunu, md. 66 (mevzuat.gov.tr) · SGK – Sağlık Uygulama Tebliği, md. 2.5.3.A (mevzuat.gov.tr)

In trio analysis, the mother and father are tested together with the affected child. This shows whether a change came from the mother, from the father or arose anew. This information makes the result easier to interpret. It has also been shown that this approach leads to a diagnosis in a high proportion of families where the parents are related.

Source: Tan TY ve ark. Trio ve tekli ekzom dizileme karşılaştırması. Eur J Hum Genet 2019 (PubMed 31320747) · Hiz Kurul S ve ark. Akraba evliliği olan ailelerde trio ekzom. Brain 2022 (PubMed 34791078) · MedlinePlus Genetics – What do the results of genetic tests mean?

In people with the same genetic condition, the symptoms can be very different. In one person the condition may be mild, in another severe. This is called variable expressivity. It can be seen even within the same family and can make diagnosis harder.

Source: MedlinePlus Genetics – What are reduced penetrance and variable expressivity?

The test finds a gene change, but it is not known whether it is linked to disease. This change is called a variant of uncertain significance (VUS). Such a result neither makes nor rules out a diagnosis. The assessment may change as new knowledge emerges or as family members are tested.

Source: NHGRI Talking Glossary – Variant of Uncertain Significance (VUS) · MedlinePlus Genetics – What do the results of genetic tests mean?

The disease-causing gene is on the X chromosome. Males have only one X, so the disease is most often seen in males. Because females have two X chromosomes, they may have mild symptoms or none at all. A father does not pass an X-linked disease to his son.

Source: NHGRI Talking Glossary – X-Linked · MedlinePlus Genetics – What are the different ways a genetic condition can be inherited?