GENETIC COUNSELLING Gene and chromosome disorders Genetics can also affect the health of babies. Single gene disorders are caused by a problem in a single gene and families. Examples of single gene disorders are and . occur when all or part of a chromosome is missing or extra, or if the structure of one or more chromosomes is not normal. Most chromosome disorders that involve whole chromosomes do not run in families. run in cystic fibrosis sickle cell anaemia Chromosome 1 disorders WARM UP • What is a gene ? MORE A chromosome is a DNA (deoxyribonucleic acid) molecule with part or all of the genetic materiai (genome) of an organism. 1 When to see a doctor Women should talk to their doctor about their and their partner’s before becoming pregnant. This information can help doctors to if there are any genetic risks. Depending on the genetic risk factors, doctors might suggest that women meet with a genetic professional. Some reasons a person or couple might need are: family health histories find out genetic counselling a family history of a genetic condition, , chromosomal disorder, or cancer; birth defect two or more , a , or a baby who died; pregnancy losses stillbirth a child with a known inherited disorder, birth defect, or intellectual disability; a woman aged 35 or older who is pregnant or plans to become pregnant; test results that suggest a genetic condition is present; increased risk of getting or a genetic disorder because of one’s ethnic background; passing on people who want to have children together. related by blood Genetic testing? During the consultation, the genetics professional will discuss or diagnose, confirm, or find out about a genetic condition. Some tests can help couples to know what the are that a person will get or pass on a genetic disorder. The genetics professional can help couples decide if genetic testing is the right choice for them. genetic risks chances 1 DO The vast majority of babies in the world are born healthy, i.e. without birth defects. The percentage is: a. 90-91%; b. 94-95%; c. 96-97%. 1