Genotyping for Progress in Hemophilia





Managed by ATHN, a safe and secure database of medical data collected from people with bleeding and clotting disorders to be used to evaluate care, research and advocacy.

amino acids

Small molecules that are the components of proteins. There are 20 different kinds of amino acids in living things. Proteins are composed of different combinations of amino acids assembled in chain-like molecules.


bleeding disorders

A group of conditions in which a person's body cannot properly develop a blood clot, causing an increased chance of bleeding.



A person who has the gene for a condition, and may or may not display the symptoms. However, they can pass the gene on to their children.


Often called "the building block of life," cells are the smallest structural and functional unit all living organisms.

chronic disease

An illness that lasts for a long period of time or indefinitely. In contrast, an acute disease is one with a rapid onset and a short but usually severe course.


Thread-like, gene-carrying bodies in the nucleus of a cell. Chromosomes are composed primarily of DNA and protein.


Clinical Laboratory Improvement Amendments, which are federal regulations to ensure quality clinical laboratory testing.

clotting factors

Proteins in the blood that act in sequence to stop bleeding and form a clot.


The process of forming a blood clot.


data repository

A safe and secure place (database) to store medical information collected from people. This data can be used at a later time in research studies.

DNA (deoxyribonucleic acid)

A large molecule that stores the genetic code for how the proteins are made. DNA is composed of sugars, phosphates and bases arranged in a double helix shaped molecular structure. Segments of DNA in chromosomes correspond to specific genes.

dominant inheritance

Inheritance of a mutation from one parent only (or arising anew during egg or sperm formation) can be sufficient for the person to be affected.



Regions of a gene that code for protein.


factor product

Treatment that is infused into the blood stream to replace the body's missing clotting proteins. It can be made from human plasma (plasma-derived) or recombinant proteins (genetically engineered).

factor VIII deficiency

One of several proteins in the blood that acts to stop bleeding by forming a clot. Deficiency of normal factor VIII is called hemophilia A.

factor IX

One of several proteins in the blood that acts to stop bleeding by contributing to the formation of a clot. Deficiency of normal factor IX is called hemophilia B.

family history

The family structure and relationships within the family, including information about diseases in family members. Family history provides a ready view of problems or illnesses within the family and helps to understand and analyzethe inheritance or familial patterns.



A sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic.

gene therapy

A method of supplementing, manipulating, or replacing a mutated gene with a functioning one. This technique is currently being researched in several inherited diseases, including hemophilia.

Genetic Alliance

A health advocacy organization committed to transforming health through genetics and promoting an environment of openness centered on the health of individuals, families, and communities.

genetic heterogeneity

Refers to diseases, conditions or other characteristics that appear similar but whose genetic basis is different in different populations or individuals.

genetic test

A test to detect the presence or absence of, or change in, a particular gene or chromosome. Also referred to as genotyping.


The complete genetic sequence for an organism.


A description of the gene mutation that is causing a certain condition or disorder (e.g., hemophilia).


A laboratory analysis of DNA to determine the specific mutation responsible for a person's hemophilia.

Genetic Information Nondiscrimination Act (GINA)

Signed into law in 2008, prohibits insurance companies from using genetic information to make decisions about a person's health insurance eligibility, premium or coverage terms.



NHF's information resource center on hemophilia and other bleeding disorders.


A rare chronic genetic bleeding disorder in which one of the proteins needed to form blood clots is missing or reduced; can cause prolonged periods of internal bleeding.

hemophilia A

A deficiency or absence of factor VIII. The most common form of hemophilia, also called "classic hemophilia".

hemophilia B

A deficiency or absence of factor IX. Also called “Christmas disease” after the first family diagnosed with the disorder.

hemophilia treatment centers (HTCs)

A group of federally funded hospitals that specialize in treating patients with bleeding disorders.


A physician who specializes in blood disorders.

hereditary disease

Condition that is genetically passed down from parent to child.



A way to deliver treatment to people with bleeding disorders intravenously. This method is used to introduce clotting factor concentrate directly into a vein where it can go to work immediately in their blood stream.


The biological process of transmitting characteristics or conditions from parents to child.


An antibody to infused clotting factor concentrates, which makes standard treatments less effective or ineffective.



The area where two bones are attached for the purpose of permitting body parts to move. A joint is usually formed of fibrous connective tissue and cartilage.



Two genes or markers that are so close together on a chromosome that they are rarely separated. Linkage analysis is a statistical method for detecting linkage between a disease and markers of known location by following their inheritance in families.

low to no cost

The genotyping test will be offered free of charge; however, individual HTCs may ask a participant to pay for costs associated with his/her clinic visit. Anyone interested in participating should speak with his/her HTC about these potential charges and how to potentially minimize or eliminate them prior to being genotyped.



A gene or other segment of DNA whose position on a chromosome is known and whose inheritance can be monitored.


So small it cannot be seen without the aid of microscope.

mild hemophilia

A categorical term used to describe someone with a factor VIII or IX level ranging from 5% to 40% of normal blood levels of factor.

moderate hemophilia

A categorical term used to describe someone with a factor VIII or IX level ranging from 1% to 5% of normal blood levels of factor.


Any heritable change in the DNA sequence; usually refers to a rare and harmful change in the DNA sequence that is present in less than 1% of the population.


nucleic acid

Individual units — adenine (A), cytosine (C), guanine (G), and thymine (T) — on a strand of DNA. Pairs of nucleic acids form rungs on the ladder-like structure of DNA.



The progeny, or young, born to a person.

on demand

Treatment with factor to stop bleeding after a bleed occurs.



Tiny "plate-like" components of blood that help to form clots and stop bleeding.


Preventive treatment regimen for people with hemophilia in which factor is infused on a regular basis.


Large, complex molecules that are composed of one or more chains of amino acids. Proteins can serve a wide variety of functions within the body. Proteins may be enzymes, hormones, antibodies, structural components, or gas-transporting molecules.


research sample repository

A safe and secure database to store blood or tissue samples collected from people. These samples can be used at a later time in research studies.


Nucleic acid produced by copying DNA, through a process called transcription. It is usually single stranded and has a specific sequence of nucleotides, which is complementary to the DNA sequence.



The specific order of nucleic acids on a strand of DNA. This sequence constitutes genetic information.

severe hemophilia

A term used to describe someone with a factor VIII or IX level below 1% of normal blood levels of factor.

spontaneous mutation

The change in a person's DNA that results in the development of a hereditary disease, such as hemophilia, where there is no family history of the disease.


von Willebrand's disease

A bleeding disorder in which a blood protein called von Willebrand factor is either missing or does not function properly. Von Willebrand disease is the most common bleeding disorder and can be inherited by both men and women equally.


X chromosome

One of the two sex chromosomes of humans. Females have two X chromosomes, while males have one X and one Y chromosome.


A gene that is carried by an X sex chromosome.


Y chromosome

One of the two sex chromosomes of humans. Females have two X chromosomes while males have one X and one Y chromosome. The Y chromosome carries a male-sex-determining gene that initiates development as a male.