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Genetics is the study of genes. Our genes carry information that gets passed from one generation to the next. For example, genes are why one child has blonde hair like their mother, while their sibling has brown hair like their father. Genes also determine why some illnesses run in families and whether babies will be male or female.
Genes are sections of DNA (deoxyribonucleic acid) that are found inside every human cell. They’re so tiny that they can be seen only under a powerful microscope. DNA is made of four chemicals that form pairs in different combinations. The combinations create codes for different genes. Each person has about 20,000 genes. The genes code for different traits, such as eye color, body type, or male or female sex.
Inside each cell, DNA is tightly wrapped together in structures called chromosomes. Every normal cell has 23 pairs of chromosomes (for a total of 46):
To form a fetus, an egg from the mother and sperm from the father come together. The egg and sperm each have one half of a set of chromosomes. The egg and sperm together give the baby the full set of chromosomes. That’s how we can inherit some things from our mother and some from our father.
A genetic disorder happens when a gene (or genes) has a problem with its code, and this causes a health problem. Sometimes a genetic disorder happens when a child inherits it from one or both parents. Other times, it happens only in the child (and the parents do not have the genetic disorder).
Different things can cause a genetic disorder, such as:
Scientists are learning more and more about genetics. A worldwide research project called The Human Genome Project created a map of all human genes. It shows where the genes are located on the chromosomes. Doctors can use this map to find and treat or cure some kinds of genetic disorders. There is hope that treatments for many genetic disorders will be developed in the future.
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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