PA Genetic Services Program
“To promote healthy lifestyles, prevent injury and disease, and to assure the safe delivery of quality health care for all Commonwealth citizens.”
What is genetics?
Your family history holds key information about your past that can unlock clues about you or your children’s future health. Genetics is the branch of medicine that looks at how hereditary and genetic factors play a role in causing a disease, birth defects, or inherited susceptibility to a health problem such as cancer or heart disease. Almost all disease is a result of the link between our genes and the environment. Genetic specialists provide individuals and families with information about inherited diseases, how they are passed down in their family, and the affects to their health. Genetic services can include physical exams, health histories, diagnostic and laboratory tests, and genetic counseling. Genetics may be complicated, but professionals can help make it clearer. Genetic counselors and medical geneticists are specialists that are available to provide in-depth counseling about heritable disorders and determine if you could be at risk.
Genetics Influence In Our Lives
Individuals seek genetic services before and while pregnant to determine if the baby is at increased risk for birth defects and genetic conditions or if a medication or drug could affect the development of their baby. Birth defects are related to both genetic and environmental factors. A genetics professional can help if a birth defect is detected during a pregnancy.
Genetic services are also important for newborns. All newborns in Pennsylvania are tested at birth for 29 genetic diseases. Newborn screening is a powerful tool for the early identification and treatment of certain disorders. In the United States it is estimated that 3-5% of all babies are born with a genetic condition, birth defect or mental retardation. Five to ten percent of all children have learning disabilities or mental retardation. Genetic factors play a role in many forms of mental retardation. If the exact cause of the mental retardation can be determined it could alter the medical management of the child.
Genetic services have now evolved into testing adults for a genetic likelihood for such disorders as cancer and heart disease. Understanding the genetic causes of disease can help to develop better prevention and treatment planning. Knowing your genetic health history can allow your physician to see the bigger picture.
For all Pennsylvanian’s it is important to know their family medical history. Many health problems run in families because families live in the same environment, share the same habits, lifestyles and genes.
What is a family history?
In medicine, a family history is part of a person’s medical history. Questions are asked to find out whether a person has tendencies toward a particular disease based on their family’s combination of shared genes, environment, behaviors and culture.
How is a family history helpful?
Knowing your family history can give you a lot of information about your health risks and the risks for your children.
- It can help you learn about diseases or conditions that you have a risk for getting
- It can point out behaviors (smoking or lack of exercise) or environmental exposures (secondhand smoke, farm chemicals) that may increase your risk or your children’s risk for disease
- It can help you and your doctors know what health problems you should be on the lookout for in yourself and your children so that problems can be found early or prevented
Where can I learn more about how my family history affects my health?
The United States Department of Health and Human Services has information about how you can ask your family about your family history. Use their family history tool to record your family history and see what you can learn.
Understanding Genetics - Genetics 101
What's the difference between chromosomes, DNA and a gene?
Your body is made up of trillions of cells. In each cell there are normally 46 chromosomes. We get 23 chromosomes from our mother and 23 chromosomes from our father. Therefore, our chromosomes come in pairs. The chromosomes are made up of DNA. The DNA or deoxyribonucleic acid is a chemical code or instructions that direct how your body is developed. Each chromosome has very specific chapters that tell the cell what kinds of characteristics you will have (like eye color and hair color). Each of these chapters that code for a specific trait is called a gene. Genes are small pieces of DNA that have information about your characteristics.
Why do you sometimes inherit certain traits from your parents and sometimes you don't?
Genes, like the chromosomes, come in pairs. Each person receives one copy of a gene from their mother and one from their father. Even though you get half of your genes from your mother and half from your father, sometimes one gene is dominant over the other gene. An example would be the genes for eye color. The gene that gives you brown eyes is dominant over the gene that gives you blue eye color. Dominant genes are always shown, regardless of what the other gene is that a person has. A person with brown eyes can have either two “brown” genes or one “brown” gene and one “blue” gene. People with blue eyes must have two copies of the “blue” gene (one from each parent). When you need two copies of a non dominant gene to show the characteristic, it is called a recessive trait. If a person has one dominant gene and one recessive gene, they are called a carrier. This is because they show the dominant characteristic, but "carry" the recessive gene. It is possible for two brown eyed parents to have a blue eyed child if both parents are “carriers” for the recessive gene. Many genetic conditions are also inherited this way, such as: Cystic Fibrosis, Sickle Cell Anemia and Tay Sachs Disorder. These are genetic conditions that are due to recessive genes. These conditions have an equal chance of appearing in both males and females.
What are Single Gene Disorders?
Genetic disorders can result when there is a mistake in the genetic code of a single gene. Genes carry the bits of information which determine the growth and function of a person. Genes are like recipes to build everything in our bodies. We have two copies of every gene, one from the mother and one from the father. Some genetic conditions result when there is only one of the gene pairs that has been changed or altered. A dominant condition is when one gene is changed and it affects health, growth, or development. If both of the genes are mutated before a person has symptoms, it is called a recessive condition. An example of a single gene disorder that is inherited as a dominant disorder is Huntington’s Chorea. Sickle cell anemia is a genetic disorder that is inherited as a recessive condition. Single gene disorders are inherited by different patterns of inheritance; autosomal dominant, autosomal recessive, and x-linked.
What are Chromosome Disorders?
Each of our body’s cells has 46 chromosomes. Each of the chromosomes is made up of thousands of genes. The first 22 pairs of chromosomes are identical and are called autosomes. The last pair of chromosomes is called the sex chromosomes. In males there is a Y chromosome and one X chromosome. In females there are two X chromosomes. Genetic disorders can occur when there are extra or missing chromosomes. It is also possible that only part of a chromosome is missing or a rearrangement has happened between chromosomes (translocation). Any time there are missing or extra chromosomes, birth defects and/or mental retardation can occur. An extra chromosome would mean that there are thousands of extra copies of genes. A missing chromosome would mean there are missing genes.
What causes a baby to have an extra chromosome as in Down Syndrome?
Down syndrome is a genetic condition that is caused by an extra copy of the 21st chromosome. Before parents can make a baby, certain cells in the ovaries and sperm must divide so that the child does not get too much DNA. Each cell that will make the baby must have exactly 23 chromosomes. When the cell from the mother (the egg) merges with the cell from the father (the sperm), the baby will have its full 46 chromosomes. These parental cells must go through a very specific kind of division called meiosis where new cells have exactly half the genetic material. During this division, chromosomes that encode the same kinds of genes must line up next to each other. They then split away to the 2 new cells.
Sometimes they "stick" together, leaving one cell with one extra and one cell with one fewer chromosome. This is called nondisjunction. Then the baby will have too many or not enough chromosomes when the sperm and egg merge. This is what happens in Down Syndrome. Chromosome 21 doesn't separate properly. The child then gets one extra chromosome from either the mother or the father. Instead of having 2 copies, the child gets 3.
What does genetics have to do with cancer?
Genetics is related to cancer in that cancer results from mutated genes. Sometimes these genes are passed down through families putting them at greater risk for getting cancers. Three major events happen to turn a normal cell into a cancerous (or malignant) one.
Guide to Genetic Services
Who should see a genetics professional?
Talk with your doctor if you are interested in a genetics assessment. Some reasons to get genetic consultation are:
Delays in mental and physical development
Families in which more than one person has the same condition or disorder
Couples with multiple miscarriages, stillborns or infertility
Abnormal prenatal screen results
Exposure to an environmental agent
Medications or alcohol use in pregnancy
Early onset cancer in the patient or family
What is a genetic consultation and genetic counseling?
A genetics consultation is the evaluation of a person’s health and family history to see if they have a genetic condition, or genetic likelihood to a health problem. Genetic counseling gives the patient the chance to have a talk with a trained health professional to discuss their risk for a genetic condition and to figure out if they want to get further testing. A physical exam may be done to look for symptoms of a certain genetic condition. One of the goals of the consultation is to confirm, diagnose or to rule out a genetic condition. During the appointment the patient will be given information on the limitations, benefits and risks of a genetic test. Genetic professionals will also talk to the patient about how to deal with medical issues related to the genetic condition or genetic likelihood. They also give families information about genetic condition and possible genetic testing and provide education about testing procedures, diagnosis, prognosis, available options, recurrence risks and support services. Genetic professionals are trained to help patients understand genetic inheritance patterns and what causes the specific genetic condition.
What is genetic testing?
Genetic testing involves a laboratory test to look at a person’s genetic material in their body. This can involve looking at the DNA, RNA, chromosomes, proteins or certain metabolites. This is usually done with a blood, saliva or tissue sample. It can also be done in a pregnancy with amniotic fluid and chorionic villi. Genetic testing should only be done after genetic counseling to ensure that the patient understands the benefits and limitations of the specific test that is ordered. It is important to note that genetic test results can apply not only to the patient, but may also give information about other family members. Genetic tests are usually done by special labs.
Who are genetics professionals?
Genetic professionals are medical geneticists, genetic counselors and genetic nurses. A medical geneticist is a doctor who specializes in the diagnosis and treatment of genetic disorders. Most medical geneticists are pediatricians, internists and obstetricians that have received at least an additional two years of training in clinical genetics and are board certified by the American Board of Medical Genetics. Genetic counselors are professionals who have a master’s degree in genetic counseling and are certified by the American Board of Genetic Counseling. Genetic counselors are trained in explaining genetic information to families.
What questions should you ask your genetics provider?
- What caused the specific genetic condition or genetic likelihood in the family?
- What are the features of the genetic condition?
- How is this condition treated?
- Could it happen again to another child?
- Is there a genetic test that could confirm the diagnosis?
- How accurate is the genetic testing for this condition?
- What are the support services available in the area for this condition?
- Is there financial help available for individuals with this condition?
- Are you a board certified genetic counselor or medical geneticist?
Why consider a genetic test?
Knowledge of a genetic condition or likelihood can change your medical and life choices. Prevention is the key to many health conditions. Genetic testing can give you information to make good health choices.
When Does A Couple Need Genetic Services?
Prior to becoming pregnant, there are many things a couple can do to lower the chance of birth defects and genetic conditions.
renatal vitamins with folic acid before you get pregnant.
Talk to your doctor about screening you and your partner to determine if you are a carrier for genetic conditions that are common in specific ethnic groups, such as Cystic Fibrosis in Northern Europeans, Sickle Cell Anemia in African Americans, and Tay Sachs disease in Ashkenazi Jews. Early identification of these genetic conditions can affect the treatment.
Learn more about your family medical history on both the maternal (mother) and paternal (father) sides of your family and your partner’s family. Write this information down and bring it to your doctor.
Talk to your doctor if you have any concerns that a medication, drug or other exposure could affect your future children.
Prenatal Genetic Testing is one way a woman can improve the chance to have a healthy baby. Approximately 95% of women who have prenatal genetic testing receive good news from the test results. Some of the tests that can look at the genetic health of the baby include chorionic villus sampling (CVS), amniocentesis, ultrasound, and maternal blood testing. It is important to learn all you can about a procedure or test itself, as well as its purpose, risks, benefits, and limitations. Some of the prenatal genetic testing, such as maternal blood testing is only a screening test. A screening test will tell you that there is an increased risk for a genetic condition or birth defect and further diagnostic testing is needed to determine if there is a problem. Other genetic tests, like amniocentesis, are a diagnostic test which will tell you if there is a specific genetic condition. These tests are all done at different weeks of the pregnancy, so you need to talk to your doctor about prenatal genetic testing before or early in the pregnancy.
Common Reasons for a preconception/prenatal genetic referral:
- Mother will be 35 years or older at delivery
- Abnormal results from a multiple marker screen or fetal ultrasound
- Personal or family history of a known or possible genetic condition, birth defect or chromosome abnormality
- Exposure to a chemical/drug/environmental agent that is known or possible to cause a birth defect
- Mother with a medical condition known or possible to affect the development of the baby (i.e., seizures and diabetes)
- Two or more pregnancy losses
- Close biological relationship of the parents (first cousins or closer)
- Ethnic likelihood to certain genetic conditions
When Does A Child Need Genetic Services?
If one or more of the following applies to a child you know, he or she might need genetic services. Contact their healthcare provider for more information about referrals.
| Birth Defects
|| Unusual Physical Features|
|| Ears |
| Cleft lip and/or cleft palate
|| Ear pits or tags |
| Congenial heart disease
|| Unusually shaped ears |
| Diaphragmatic hernia
| Genital malformations
|| Different colored eyes |
|| Down slanting eyes |
| Misshapen skull
|| Epicanthal folds |
| Missing fingers or toes
|| Up slanting eyes |
| Missing or incomplete limbs
|| Wide-spaced eyes |
| Spina bifida
| Other congenital anomalies
|| Face |
|| Facial asymmetry |
| Chronic Disease
| Bleeding disorders
|| Hair |
| Childhood cancers
|| Brittle or sparse hair |
| Kidney or urinary tract disease
|| Excessive body hair |
| Slow growth or short stature
|| White patch of hair |
| Cystic fibrosis
| Degenerative disease
|| Large or small tongue |
| Other chronic disease
|| Misshapen teeth |
|| Missing or extra teeth |
| Developmental Problems
|| Smooth philtrum |
|| Thin upper lip |
| Attention deficit/hyperactivity
| Developmental delay
|| Skeletal |
| Failure to thrive
|| Loose joints |
| Learning disability
|| Unusually tall or short stature |
| Low muscle tone
|| Webbing between fingers or toes |
| Mental illness
| Mental retardation
|| Skin |
|| Excessive skin |
| Speech problems
|| Increased or decreased sweating |
|| Many birthmarks |
|| Any other unusual features |
| Extreme farsightedness
| Extreme nearsightedness
| Hearing loss
What is a pediatric geneticist?
Pediatric geneticists are doctors with special training in pediatrics and genetics. They are able to recognize rare genetic conditions in children and help families of children with these conditions to receive appropriate medical care. Pediatric geneticists often work with genetic counselors. Genetic counselors are people who are trained to give families information about genetics and genetic conditions.
Who should see a pediatric geneticist?
There are many different things that bring children and their families to a pediatric geneticist.
Children who are known to be at risk for a genetic condition because someone in their family has a genetic condition
- Children with more than one birth defect
- Children with developmental delays or mental retardation that does not have a known cause
- Children with multiple unexplained health problems whose parent or physician requests evaluation
Why should I see a pediatric geneticist?
When children have health conditions, their parents often have questions like:
- Why does my child have this health condition?
- Could my future children or my child’s children have a similar health condition?
- Where can we get more information?
Sometimes it is difficult to get clear answers to all of these questions; however, a genetic specialist can help give information about these rare conditions.
What does a pediatric geneticist do?
An initial outpatient visit usually lasts about 90 minutes. The patient is examined and, with permission, photographs may be taken. At the end of the visit, all findings are reviewed with the patient's family and recommendations are made. During the visit, expect the geneticist and genetic counselor/genetic nurse to:
- Work with the family to outline their family history and a three-generation family history, including both sides of the family. This family history, also called a pedigree, may reveal an underlying genetic issue in the family.
- Diagnose and provide detailed information about genetic conditions.
- Recommend and interpret genetic testing and give the family more information about the child’s health condition.
- Recommend appropriate treatment and coordinate care.
- Refer to resources.
When Does An Adult Need Genetic Services?
If any of the following applies, it could indicate the need for genetic services. Contact your healthcare provider for more information about referrals.
| Ethnic Background
|| Family History |
| Jewish or French Canadian
|| Acute intermittent porphyria |
| Afro-American or East Indian
|| Auto immune diseases |
| Asian, Greek, or Italian
|| Alzheimer’s disease |
|| Birth defects |
| Medical History
|| Blindness |
| Birth defects
|| Cancer - especially breast or colon |
|| Cleft lip or palate |
|| Congenital heart disease |
|| Cystic fibrosis |
| Carrier status for inherited disorders
| Degenerative diseases
|| Degenerative disease |
| Hearing loss
|| Down syndrome |
| Mental retardation
| Mental illness
|| Early onset (under 35) cancer |
| Other genetic disease
|| Early onset (under 35) emphysema |
|| Early onset (under 35) heart disease |
| Reproductive History
|| Fragile X syndrome |
| Advanced paternal age (45 or older)
| Advanced maternal age (34 or older)
|| Hemophilia or bleeding disorder |
| Two or more miscarriages
|| Huntington’s disease |
| Previous children with birth defects
|| Infant or childhood death |
| Previous children with learning delays
|| Mental retardation |
| Unexplained infertility
|| Muscular dystrophy |
|| Phenylketonuria |
| Pregnancy Exposures Including:*
|| Polycystic kidney disease |
|| Sickle cell trait |
| Cat litter box
|| Spina bifida |
|| Tay-Sachs carrier |
| High fever
|| Thalassemia trait |
|| Other genetic disease |
| Prescription and other medications
| Recreational drugs
| Pregnancy complicated by medical problems such as asthma, lupus, diabetes, seizures, etc.
Adults with Genetic Disorders
What is the adult genetics clinic?
Adult genetics focuses on the care of patients over 18 years of age. The typical focus includes: diagnostic evaluation of conditions with a suspected genetic basis in adults; providing care for adults with established genetic conditions; genetic counseling and testing services for people with a known family history of a genetic condition; preconception counseling; and testing for people considering pregnancy who may be at risk for having a child with a genetic condition.
Who should be referred to an adult genetic clinic?
Many genetic conditions are identified and diagnosed at birth or during childhood. These people, once they reach adulthood, need to be switched from pediatric care to adult care, and are referred to an adult genetics clinic for management of their genetic condition.
Examples of these types of genetic disorders include:
Fragile X Syndrome
Other Heritable Conditions and Genetic Syndromes
Other types of genetic conditions may manifest themselves after childhood and adolescence. These are known as adult onset genetic conditions and require a genetics evaluation for diagnosis and management.
Examples of adult onset genetic conditions include:
Adult genetic clinics are primarily based on patients being referred by a physician. Medical records should be sent from the primary care physician and/or referring sub specialist prior to the patient’s appointment. During the genetics visit, the patient may meet with both a genetic counselor and a medical geneticist. For genetics patients requiring special diets, a dietician will be available as well. The physician will obtain a detailed family history, a physical exam, and laboratory testing as needed. Genetic testing will be offered only if available and appropriate for the patient. It is the responsibility of the patient to check with his or her insurance company regarding payment for genetic services.
Resources and Publications
Bureau of Family Health
Division of Newborn Screening & Genetics
Health & Welfare Building, 7th Floor East
625 Forster St.
Harrisburg, PA 17120