As you and your partner prepare to start your family or perhaps you are having your second or third child, there are so many advances in technology today to insure you have a safe and uneventful delivery. Usually with advanced age of the mother, genetic counseling is advised. However, it is also in order to consult with a geneticist if you know of family predisposition to genetic disorders. A geneticist can help you with questions about genetic disorders in your family line. Here below are some terms to become familiar with before your first visit.
Abdominal Wall Defect. An abnormal opening in the abdominal wall structures of the fetus near where the umbilical cord inserts into the fetal abdomen and through which the some of the abdominal contents protrude out.
Alphafetoprotein (AFP). A substance made by the fetus that is present in amniotic fluid and maternal blood. AFP levels are measured during pregnancy to screen for neural tube defects and abdominal wall defects.
Amniocentesis: A prenatal diagnostic procedure done by inserting a thin needle through the woman's abdomen to obtain a small amount of amniotic fluid. The fluid is used to perform prenatal testing including chromosome analysis, AFP measurement and, on occasion, other genetic tests.
Amniotic Fluid. The watery fluid that surrounds the fetus. The fluid is made by the fetus and contains cells on which genetic testing can be performed.
Anencephaly. A neural tube defect that is usually fatal, in which there is an opening in the skull of the fetus and brain tissue is missing.
Autosomal Recessive. A type of genetic inheritance in which both parents must be carriers in order for a child to have the condition. Autosome: Any chromosome other than the sex chromosomes.
Birth Defect. An abnormality present at birth, such as Down syndrome or spina bifida. Birth defects can have many different causes. Not all birth defects can be detected by prenatal genetic testing or ultrasound examination.
Bloom Syndrome. A rare autosomal recessive disease associated with growth problems, an increased risk of cancer and shortened life span. The disease is more common in individuals of Ashkenazi Jewish descent.
Canavan Disease. A severe autosomal recessive disease that causes mental retardation, motor skill and feeding problems, and death early in childhood. The disease is more common in individuals of Ashkenazi Jewish descent.
Carrier. A person who has one normal copy of a gene and one altered gene. A carrier is usually not affected with the genetic condition, but has an increased risk for having an affected child.
Carrier Testing. Genetic testing designed to detect whether or not a person is a carrier for a genetic disease. This term often refers to DNA testing for a genetic disease. This type of test is often performed on a blood sample.
Chorionic Villi Sampling (CVS). A prenatal diagnostic procedure usually done between 10 and 12 weeks of a pregnancy, in which a small sample of developing placental tissue is obtained. The tissue can be obtained either by inserting a thin tube through the woman's cervix or a thin needle through the woman's abdomen. This placental tissue has cells that can be used for genetic testing.
Chromosome. Structures inside every cell that contain thousands of genes. A human cell contains 46 chromosomes (23 pairs), half from the egg and half from the sperm.
Chromosome Abnormality. If all or part of a chromosome is missing or duplicated, the missing or extra genes usually cause serious birth defects.
Cystic Fibrosis (CF). An autosomal recessive disease in which thick mucous builds up in the lungs, gastrointestinal tract and reproductive systems. This build-up leads to pneumonia, diarrhea, poor growth, infertility and shortened lifespan. The disease is most common in individuals of Caucasian and Ashkenazi Jewish descent.
DNA(deoxyribonucleic acid). The chemical material or blueprint packaged within the genes that is passed from one generation to the next. DNA determines the structure and function of all living things.
Down Syndrome. A condition caused by an extra copy of the chromosome #21 that leads to mental retardation (usually mild to moderate), heart defects and characteristic facial features.
Ethnic Background (ethnicity). A race or a family's national origin.
Familial Dysautonomia. A rare autosomal recessive disease that affects the nervous system and causes temperature regulation problems, unstable blood pressure, pain insensitivity, vomiting, frequent pneumonia and poor growth. Typically, it is not associated with mental retardation. The disease is most common in individuals of Ashkenazi Jewish descent.
Fanconi Anemia C. An autosomal recessive disease that causes early childhood anemia, growth problems, birth defects and cancers. The disease is most common in individuals of Ashkenazi Jewish descent.
Fetus. The term used to describe the developing baby between three months of pregnancy to birth.
Fragile X Syndrome. A disorder caused by a gene located on the X chromosome. Fragile X syndrome is the most common cause of inherited mental retardation and autism. Both males and females can be affected with fragile X syndrome or can carry the gene but not show any symptoms.
Gaucher Disease. An autosomal recessive condition that causes fatigue, an enlarged liver and spleen, easy bruising and bleeding, bone pain and/or fractures. In the most severe form (which is rare), the brain and nervous system are also involved. The disease is most common in individuals of Ashkenazi Jewish descent.
Gene (and altered gene). A unit of genetic information made of DNA that is a "blueprint" for the structure and functioning of cells. Human beings have over 30,000 different genes. An altered gene, also sometimes called a mutation, is a permanent change in the gene that can alter its ability to function properly and lead to genetic diseases.
Genetic Counselor. A health care professional trained in the field of genetics who reviews a person's family and medical history and determines the risks for possible diseases or conditions. Genetic counselors explain the benefits, risks and limitations of testing options and procedures and facilitate patient decision-making regarding these options.
Genetic Disease. A condition caused by a change in a gene or many genes. While many diseases may have genetic factors involved, a genetic disease usually refers to something that is hereditary or passed from generation to generation.
Gestational Age. The age of the developing fetus.
Glycogen Storage Disease Type 1a (GSD1a). An autosomal recessive disorder caused by a problem in the enzyme responsible for the release of glucose from glycogen. Affected individuals may experience low blood sugars, growth retardation, enlarged liver and bleeding disorders.
Hemoglobin. A chemical in blood that delivers oxygen to cells.
Hemoglobin Disorder (hemoglobinopathy: A disorder in which the structure or shape of hemoglobin is changed and, as a result, has its function affected. Examples of hemoglobin disorders are alpha or beta thalassemia and sickle cell anemia. Hemoglobin disorders are more commonly found in individuals of African, Middle Eastern, Mediterranean, Asian and certain Hispanic ethnic backgrounds.
Hereditary. Passed from generation to generation.
Maternal Age. The age of the mother of a pregnancy, usually her age at delivery. The risks of having a pregnancy with a chromosome abnormality increase as women age.
Maternal Serum Screening. A blood test done during pregnancy that determines whether there is an increased risk for birth defects such as Down syndrome or spina bifida.
Mucolipidosis Type IV. An autosomal recessive disease that affects the brain and nervous system. Symptoms begin in first year of life and consist of visual problems and severe mental retardation. The disease is most common in individuals of Ashkenazi Jewish descent.
Neural Tube. The structure formed in the first six weeks of pregnancy that forms the spinal column which surrounds the spinal cord and brain.
Neural Tube Defect. A birth defect that involves an opening anywhere in the spinal column from the skull to the bottom of the spine.
Niemann-Pick Type A. An autosomal recessive disease that causes poor growth, mental retardation, physical problems and death early in childhood. The disease is most common in individuals of Ashkenazi Jewish descent.
Placenta. The structure attached to the wall of the uterus in which the fetus is growing. It has many blood vessels to supply nutrients to the fetus through the umbilical cord.
Sex Chromosomes. The X and Y chromosomes. A fetus with an XY set of chromosomes is male and a fetus with an XX set is female.
Sickle Cell Anemia. An autosomal recessive anemia caused by abnormal hemoglobin that makes red blood cells sickle shaped.
Soft Marker (soft sign). Sometimes seen on an ultrasound. Subtle abnormalities that are associated with an increased risk for certain chromosome abnormalities or other birth defects.
Spina Bifida. A neural tube defect that involves an opening anywhere along the spinal column.
Tay-Sachs Disease. A disease caused by a missing enzyme that leads to neurological deterioration and death in early childhood. The disease is most common in individuals of Ashkenazi Jewish descent.
Thalassemia. An autosomal recessive disease caused by abnormal hemoglobin leading to anemia.
Trisomy. A third or extra copy of a chromosome.
Trisomy 18. A severe chromosome abnormality caused by an extra chromosome 18. Most fetuses with trisomy 18 have birth defects and babies with this condition usually die within their first year.
Ultrasound (sonogram). A method of using sound waves to visualize the anatomy of a fetus and the surrounding amniotic fluid and placenta. Measurements taken from the ultrasound help determine the gestational age of the fetus, as well as find certain physical birth defects or abnormalities. Not all birth defects can be detected by ultrasound.