Glossary

gene
unit of genetic information in the genome of living organisms; a gene contains the genetic information – the blueprint – for a specific gene product (protein or RNA). In most organisms, the entirety of all genes, the genome, is present as a deoxyribonucleic acid chain (DNA), which forms the chromosomes in the cell nucleus. The information of a gene is mediated by a certain sequence of the nucleic acid building blocks adenine, guanine, cytosine and thymine.

gene therapy
an experimental form of therapy aimed at eliminating gene-related dysfunctions or restoring normal gene function in diseases that can be managed by the elimination or provision of a particular protein;
Example / Relevance Pediatrics: experimental form of treatment for some cancers
References: gene - protein

genetic
concerning the (level of) inheritance or genes; inherited

genetics
science that deals with the function of genes, their molecular structure, and the basics and laws of heredity

genomic
concerning the entire genetic material (genome) of a living being; the largest part of the genome is located on the chromosomes, a small part outside the cell nucleus in the so-called mitochondria.

germ cell tumours
embryonal, solid tumours that arise from degenerated stem cells and progenitor cells of the gonads during human development in the womb or afterwards; they occur mainly in the coccyx region, ovaries, testicles or in the central nervous system. Most common are germ cell tumours in infants and children up to 1 year of age; they account for almost 4% of all childhood and adolescent cancers.

germ cells syn. gametes
mature cells capable of sexual fertilization (eggs in women, sperm cells in men)

germline
term for those cells that are in the service of the direct transmission of genetic material, i.e. from which germ cells (egg cells and sperms) arise in the course of individual development; the germline begins with the fertilized cell (zygote) and continues through the formation of primordial germ cells to the formation of the sex glands (gonads), which are responsible for reproduction and ultimately the germ cells.
Example / Relevance Pediatrics: some germ cell tumours arise from malignant cells of the germline. In addition, the cells of the germline are also important because gene changes (mutations) in the germline (unlike somatic mutations) are passed on to the offspring.

germline mutation
mutation that occurs in the female or male germ cells (eggs or sperm) and can thus be inherited by the offspring; in the case of a germline mutation, all body cells of the offspring are usually affected by the change. In contrast, "somatic" mutations arise in somatic cells outside the germline and are not inherited.
References: mutation - germline - germ cells

glandular fever syn. Pfeiffers disease, infectious mononucleosis
common, often harmless viral disease that occurs mainly in children and young adults; is caused by the Epstein-Barr virus (EBV) and affects the lymphatic tissue (e.g. lymph nodes, spleen). Pfeiffers glandular fever is associated with characteristic changes in blood counts (conspicuous increase in white blood cells; leukocytosis).
Example / Relevance Pediatrics: Glandular fever can cause symptoms similar to leukaemias and lymphomas (e.g. swelling of the lymph nodes, fever) and must therefore be distinguished from them by a blood test.

glial cells syn. neuroglia
component of the nerve tissue; glial cells primarily form the supporting, enveloping and nourishing tissue of the nervous system.

glioblastoma
a highly malignant, rapidly growing tumour of the central nervous system belonging to the glioma group; glioblastoma originates from the nerve support tissue, the glial cells. It is classified as a grade IV tumour according to the WHO classification.

glioma
collective term for all primary tumours of the central nervous system originating from glial cells (e.g. astrocytomas, oligodendrogliomas, glioblastomas)
Example / Relevance Pediatrics: gliomas in childhood and adolescence are divided into low-grade and high-grade gliomas and are treated differently, depending on the degree of their malignancy.

glucagon
peptide hormone that is primarily responsible for increasing blood sugar levels, acting as the antagonist of insulin. Glucagon is produced in the islets of Langerhans cells in the pancreas.

gonads
primary reproductive organs (ovaries in the female, testes in the male), which are responsible for producing the male and femaile germ cells (ova, sperm)

Gorlin-Goltz syndrome (Abrev.: NBCCS) syn. Gorlin syndrome, Naevoid basal cell carcinoma syndrome, basal cell nevus syndrome
a hereditary disease associated with a number of developmental disorders and a predisposition to various cancers, the most common being a form of skin cancer (basal cell carcinoma);
Example / Relevance Pediatrics: children and adolescents with Gorlin-Goltz syndrome have an increased risk of developing medulloblastoma or soft tissue sarcoma (rhabdomyosarcoma).

GPOH
Society for Paediatric Oncology and Hematology (GPOH), the German professional society for childhood and adolescent cancers and blood diseases; in the GPOH, doctors, scientists, nurses and psychologists, among others, work together on the research, diagnosis, treatment and aftercare of malignant diseases and blood diseases in children and adolescents. in the GPOH, doctors, scientists, nurses and psychologists, among others, work together on the research, diagnosis, treatment and aftercare of malignant diseases and blood diseases in children and adolescents.

graft-versus-host disease (Abrev.: GvHD)
immunological reaction that may occur after allogeneic stem cell transplantation; the donors immune cells (T lymphocytes) react against the recipients organs and tissues. Target organs are mainly skin (sunburn-like symptoms) and mucous membranes, liver (impaired liver function) and intestines (watery diarrhea). Depending on the severity and number of organs affected, four degrees of severity of graft versus host disease (GvHD) are distinguished. If the reaction occurs within the first 100 days after transplantation, it is called acute GvHD, while symptoms developing later than that are referred to as chronic GvHD. For some patients, GvHD can become life-threatening. Certain measures and medication are given to prevent GvHD as much as possible or to reduce its severity, respectively.
References: allogeneic stem cell transplantation - immunological - symptom - T lymphocytes

graft-versus-leukaemia response (Abrev.: GvL) syn. transplant-versus-leukaemia reaction
reaction in the context of an allogeneic stem cell transplant in which the donor lymphocytes target leukaemia cells in the recipients body, thereby destroying them; this reaction helps to reduce the risk of disease relapse in the transplanted patient.
References: allogeneic stem cell transplantation - lymphocytes

granulocytes
subgroup of white blood cells (leukocytes); they are mainly responsible for defending against bacteria and other pathogens (such as viruses, parasites and fungi); granulocytes are also involved in allergic and inflammatory reactions, as well as pus formation. Granulocytes make up about 60 – 70% of the leukocytes in the blood. Due to their differently colourable granules and their different tasks, they are divided into three subtypes: neutrophils (90 %), eosinophils (2 – 4 %) and basophilic granulocytes (up to 1 %). The neutrophils (neutrophils for short) play the most important role in the defense against infections.

granulocytopenia syn. neutropenia, neutrocytopenia
reduced number of (neutrophil) granulocytes in the blood; since granulocytes are important for the immune system, infections are easy to occur in patients with granulocytopenia (neutropenia). The most severe form of granulocytopenia is agranulocytosis, the (almost) complete lack of granulocytes in the blood. Granulocytopenia is the most common form of leukopenia (leukocytopenia).
Example / Relevance Pediatrics: granulocytopenia is a common side effect of chemotherapy.

gray (Abrev.: Gy)
unit of measurement for the dose of energy caused by ionising radiation (e.g. in the context of radiotherapy) and absorbed by a given mass (kilogram of body weight)
Example / Relevance Pediatrics: the unit „gray“ provides information about the radiation dose used in radiotherapy or nuclear medicine therapy.