Research & Tracking
Soon after birth, all babies born in the United States are required to be checked for certain genetic medical conditions. Finding these conditions soon after birth can help prevent some serious problems, such as brain damage, organ damage, and even death. Newborn screening-related projects include:
- New technologies used in newborn screening could affect reported birth prevalences of newborn screening conditions. Thus, CDC examined the associations between screening methods and criteria used by laboratories and the birth prevalences of certain newborn screening disorders (congenital adrenal hyperplasia, phenylketonuria, and the sickle hemoglobinopathies). [Read summary]
- The prevalence of hemoglobinopathies differs among populations. Because of the difference in distribution, public health programs have weighed the ethical versus practical implications of ethnically targeted versus universal newborn screening. CDC has reviewed the ethical implications and practical considerations of both approaches. [Read summary]
- The newborn screening system is intended to be comprehensive, including not only screening and diagnosis, but also long-term follow-up care through the health system. To improve long-term follow-up, CDC assists with the development of data systems, health indicators, and specific data elements for evaluating the newborn screening system. [Read summary]
- Looking at causes for the increase in the rate of congenital hypothyroidism in the United States, detected through newborn screening.
- Working with state public health departments to develop information systems to track infants born with disorders detected using newborn screening from birth to three years of age. In addition to conducting public health surveillance, these systems can provide data to assess coordination of care, to evaluate improvements in the quality of care, and to increase understanding of the natural history of newborn screening disorders.
- Using data from a national survey of newborn screening programs to determine how frequently vitamin B12 (cobalamin) deficiency occurs among newborns due to a B12 deficiency among mothers.
Family Health History
Families share genes. Families also can have other things in common, such as exercise habits and the foods they eat. Family members might live in the same area and come into contact with similar things in the environment. Family history includes all of these things, which can be risk factors for many conditions. Following are brief discussions of some of the genetics-related research that has been or is being done by the Centers for Disease Control and Prevention (CDC) in collaboration with various partners.
CDC is partnering with the Genetic Alliance and others on the Genetics for Early Disease Detection and Intervention (GEDDI) initiative. The goal of GEDDI is to develop a public health approach for the effective use of clinical, genetic, and family history information to enable early diagnosis of diseases that would, in turn, lead to improved health outcomes. The initial focus of this initiative will be on single gene disorders, but the initiative will be expanded in the future to include common diseases as genomics knowledge matures over the next few years. Learn more about GEDDI »
If a woman takes enough folic acid before and during pregnancy it can help prevent neural tube defects (NTDs), which are major birth defects of a baby's brain and spine. CDC worked with the Michigan and Colorado state health departments to use family history to identify women at increased risk of having a pregnancy affected by an NTD. The project focused on second-degree relatives of children with an NTD. Participants were asked about current and planned folic acid use, views on having a child affected by NTDs, and pregnancy planning. The study found that folic acid use among the relatives of children with NTDs was similar to that among the general population, even though they felt more at risk of having a child with an NTD. [Read summary]
CDC is exploring ways to improve use of family history in pediatric primary care and public health.
Determining whether children with birth defects show differences in DNA methylation compared with children who do not have birth defects.
Including genetics in research studies can help CDC learn more about risk factors and causes of birth defects, developmental disabilities, and genetic disorders. Pediatric genetics is part of several CDC studies.
National Birth Defects Prevention Study (NBDPS)
The National Birth Defects Prevention Study (NBDPS) is the largest U.S. study looking at risk factors and potential causes of birth defects. Recent research using data from NBDPS includes:
Determining whether the prevalences of different types of spina bifida vary by the mother’s race and ethnicity. [Read summary]
Evaluating whether genital tract infections are associated with birth defects [Read summary]
Studying whether birth defects are related to the father’s age. [Read summary]
Finding out if antibiotic use during pregnancy is associated with birth defects. [Read summary]
Learning whether the amount of vitamins and minerals in the mother’s diet is a risk factor for limb deficiencies. [Read summary]
Evaluating how mothers report family histories of birth defects. [Read summary]
Looking at demographics of research participants who do and those who do not provide DNA samples. [Read article]
Metropolitan Atlanta Congenital Defects Program (MACDP)
The Metropolitan Atlanta Congenital Defects Program (MACDP) is a population-based surveillance system for birth defects. MACDP collects information on infants, fetuses, and children with birth defects in metropolitan Atlanta, Georgia. Genetics-related research includes:
Determining changes in the rates of chromosome abnormalities, such as trisomy 21 or Down syndrome, and the rates of testing for them during pregnancies and among infants with birth defects.
Looking at population rates and characteristics of trisomies 13 and 18. [Read summary]
National Health and Nutrition Examination Survey (NHANES)
The National Health and Nutrition Examination Survey (NHANES) is a program of studies designed to evaluate the health and nutritional status of adults and children in the United States. The survey is unique in that it combines interviews and physical examinations.
To gain a better understanding of the roles that nutrition and genetics play in birth defects and developmental disabilities, it is important to understand how these factors normally work together. Genetics-related research includes looking at the levels of different nutrients and metabolites that women of reproductive age have in their blood to determine how these levels differ by genotype, diet, vitamin intake, and pregnancy status. Women with certain genotypes might have lower levels in the blood of certain nutrients or metabolites and this could increase their risk for having a child with a birth defect.
Autism Spectrum Disorders
Autism spectrum disorders (ASDs) are a group of developmental disabilities that can cause significant social, communication, and behavioral challenges. Scientists have learned that there are likely many causes for the many types of ASDs. Most scientists agree that genes are one of the risk factors that can make a person more likely to have or develop an ASD.
CDC’s Study to Explore Early Development (SEED) is looking at factors that might put children at risk for ASDs. One aspect of the study is to learn whether certain physical characteristics (for example, large heads) occur more often among children with an ASD than among children who don’t have an ASD. This information will help CDC find out if children with an ASD who have the same types of physical characteristics also have the same risk factors or causes for the disorder.
United States–China Collaborative Project
For more than 20 years, CDC and the Peking University Health Science Center (PUHSC) have collaborated on birth defects research. Through the China collaboration, CDC has explored topics such as folic acid and infant death rates, congenital heart defects, changes in blood levels of folic acid with different folic acid doses, and long-term evaluation of the women and children from a community intervention program. Genetics-related research includes:
- Investigating whether a person’s methylenetetrahydrofolate reductase (MTHFR) genotype affects the response to folic acid supplementation during and 3 months after termination of supplementation [Read summary]
- Researching how global DNA methylation changes in response to folic acid supplementation during and 3 months after termination of supplementation and whether a person’s methylenetetrahydrofolate reductase (MTHFR) genotype affects changes in global methylation [Read article]
- Determining immunization rates and safety among children with inborn errors of metabolism [Read summary]
- Using data from the International Clearinghouse for Birth Defects Surveillance and Research to look at the frequency of bladder exstrophy and factors associated with this birth defect [Read summary]
A gene is a part of DNA that carries the information needed to make a protein. People inherit one copy of each gene from their mother and one copy from their father. The genes that a person inherits from his or her parents can determine many things. For example, genes affect what a person will look like and whether the person might have certain diseases.
Environmental factors can include exposures related to where we live as well as behaviors such as smoking and exercise and cultural factors such as foods that we eat.
Babies with congenital adrenal hyperplasia have adrenal glands that do not make enough of certain hormones. This can cause problems with growth and development.
Babies with phenylketonuria (PKU) cannot process phenylalanine. Phenylalanine is found in most foods and can build up in the blood and tissues of a baby with PKU, resulting in brain damage. This can be prevented if a baby with PKU is put on a special diet early.
Single gene disorders are caused by a DNA mutation in one of a person’s genes. For example, suppose part of a gene usually has the sequence TAC. A mutation can change the sequence to TTC in some people. This change in sequence can change the way that the gene works, for example by changing the protein that is made. Mutations can be passed down to a child from his or her parents. Or, they can happen for the first time in the sperm or egg, so that the child will have the mutation but the parents will not. Single gene disorders can be autosomal or X-linked.
Second-degree relatives include grandparents, aunts, uncles, nieces, nephews, and half siblings.
Phenotype is how a person looks (on the outside and inside the body) due to his or her genes and the environment (for example, having a certain eye color, being a specific blood type, or being a certain height). Phenotype also can refer to how a person’s body functions, for example, whether he or she has a certain disease.
DNA methylation is a chemical addition to a piece of DNA that turns it on or off. Global DNA methylation studies look at overall DNA methylation, throughout all of a person’s DNA, rather than at specific regions.
Deoxyribonucleic acid (DNA) contains the genetic instructions in all living things. DNA is made up of two strands that wind around each other and looks like a twisting ladder (a shape called a double helix). A DNA strand has four different bases arranged in different orders. These bases are T (thymine), A (adenine), C (cytosine), and G (guanine). DNA is “read” by the order of the bases, that is by the order of the Ts, Cs, Gs, and As. The specific order, or sequence, of these bases determines the exact information carried in each gene (for example, instructions for making a specific protein). DNA has the same structure in every gene and in almost all living things.
Gene expression refers to the process of making proteins using the instructions from genes. Changes in gene expression can affect how much of a protein is made, as well as when the protein is made.
Amniotic band syndrome is thought to occur when there are tears or breaks in the lining of the sac surrounding the baby during pregnancy. Strands of material from the sac can then entangle the baby. This can cause birth defects of the limbs (for example, arms, fingers, legs, and feet) that look like amputations, or fingers or toes that are joined together.
The limb-body wall birth defect consists of limb birth defects in the baby (arms, fingers, legs, feet, etc.) that look like amputations, or fingers or toes that are joined together. In addition, the wall of the belly does not develop correctly so that most of the organs (for example, intestines, liver, and kidneys) are exposed to the liquid in the sac surrounding the baby.
Metabolites are the chemicals that are produced by the cells in the body when they break down sugars, fats, and proteins to make energy.
The genotype of a person is her or his genetic makeup. It can pertain to all genes or to a specific gene. A gene is a part of DNA that carries the information needed to make a protein. People inherit one copy of each gene from their mother and one copy from their father. The genes that a person inherits from his or her parents can determine many things. For example, genes affect what a person will look like and whether the person might have certain diseases.
- Centers for Disease Control and Prevention
National Center on Birth Defects and Developmental Disabilities
Division of Birth Defects and Developmental Disabilities
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Atlanta, GA 30333
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