This glossary includes key terms related to differences in sex development (DSD).

Adrenal gland

The adrenal glands work interactively with the hypothalamus and pituitary gland, as well as secrete hormones that affect metabolism, blood chemicals, and certain body characteristics. Adrenal glands also secrete hormones that help a person cope with both physical and emotional stress.

Adrenal profile test

The adrenal profile is a blood test done during ACTH stimulation and measures several different substances produced in the adrenal gland. Results are available in 1-2 weeks.

Adrenocorticotropic hormone stimulation test

The Adrenocorticotropic hormone (ACTH) stimulation test looks for problems of the adrenal gland. The adrenal gland produces 3 main hormones, aldosterone for salt balance, cortisol to help the body deal with stress, and testosterone which is male hormone. Some adrenal gland problems are life threatening. The test is done over 2-3 hours, requires 2 or 3 blood samples, and results are available in 1-2 weeks.

Alternate terms in DSD

Alternative terms used for the word “Disorders” in DSD are: Variations, Atypical, Disorders, Intersex.

The following terms are no longer used in the new nomenclature and classification system: pseudo/hermaphrodite, under or over virilization/masculinization, sex reversal (see Lee et al. in a 2006 Consensus Statement on Management of Intersex disorders).


Amenorrhea is a menstrual condition characterized by absent menstrual periods for more than three monthly menstrual cycles.

Androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS) is a syndrome where male infants are not responsive to androgens (testosterone). People with this syndrome are “genetically” male.

Atypical genitalia

Atypical genitalia occur when a child’s gender is in question at birth because the genitals may not appear clearly male or female.


A chromosome is a structure in the cells of your body that contains your genes. Your genes determine your traits, such as eye color and blood type.

Chromosomal Microarray Analysis

Chromosomal Microarray Analysis (CMA) is a technique that determines if there is a change in DNA copy number. Certain changes in copy number may indicate a chromosomal abnormality, such as a chromosomal imbalance, loss, or gain.


Clitoromegaly is a condition where the clitoris is larger than normal. This can be caused by hormone problems before or after birth, or for other reasons. If a clitoris is much larger than normal, it may resemble a penis.


A clitoroplasty is a procedure to improve the genital appearance. There is no role for removal of the clitoris.

Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia is an inherited condition that affects the adrenal gland. Babies born with congenital adrenal hyperplasia (CAH) cannot make enough of the hormone cortisol, which helps control energy, sugar levels, blood pressure, and how the body responds to the stress of injury or illness.


Cytogenetics is the study of chromosomes.

Denys-Drash syndrome

Denys-Drash is a syndrome in very young children characterized by kidney failure and abnormal development of the reproductive organs and urinary system.

Deoxyribonucleic acid

See DNA.


Dihydrotestosterone (DHT) is an active male hormone, measured by a blood test. Results are available in 1-2 weeks.

Differences in Sex Development

Differences in Sex Development (DSDs) are variations in the development of sexual organs, and other sex-related anatomical parts in relation to sex chromosomes (X, Y) . See a list of DSD conditions.


DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.

DNA sequencing

See Sequencing.


See Differences in Sex Development.


Electrolytes are blood chemicals such as sodium and potassium that may be abnormal in DSD that involve the adrenal gland. Results are available in a few hours.


Endocrinology is the study of hormones and other chemicals secreted by the body’s endocrine glands.


Endoscopy is a procedure where a small scope is placed into an opening in the genital region to evaluate the anatomy of the bladder system and genital system.


Epigenetics is the study of changes in the regulation of gene expression activity without altering genetic structure.


Epigenomics is the systematic study of the global gene expression changes in the genome due to epigenetic processes and not due to DNA sequence changes.


Epispadias occurs when the opening of the urethra, which is the hollow tube that drains urine from the bladder to the outside of the body, is in an abnormal location.


Estradiol is a female hormone, measured by a blood test. Results are available in 3-5 days.

Failure of pubertal development

Some individuals do not progress through puberty at the typical time.  This can be for many reasons, including hormone problems, problems in the genitourinary system, genetic conditions, or other reasons.

Fluorescence in situ hybridization

Fluorescence in situ hybridization (FISH) is the fastest chromosome test available, and results can be available in 48-72 hours. This blood test looks only at whether specific chromosomes or parts of chromosomes are present or missing. FISH is often used to determine whether a newborn baby carries two X chromosomes or an X and a Y chromosome.

Follicle Stimulating Hormone

Follicle Stimulating Hormone (FSH) is a hormone signal from the pituitary gland to the ovaries or testicles, measured by a blood test. Results are available in 24 hours.

Frasier syndrome

Frasier syndrome is a rare disorder that affects development starting before birth that includes abnormalities of the genitalia and the urinary tract.


A genitogram is a test where a contrast solution is injected into an opening in the genital region to provide an outline or roadmap of the bladder system and genital system.


A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins.


A genitoplasty is when reconstructive surgery is performed on the genital organs.


The genome is the complete set of DNA, including the genes, of an organism.


Genomics is a branch of molecular biology that studies genomes.


A gonad is an organ that produces reproductive cells (gametes). The ovaries and testes are gonads.

Gonadal dysgenesis

Gonadal dysgenesis is the defective or abnormal development of the gonads.

Human Chorionic Gonadotropic stimulation test

A human Chorionic Gonadotropin (hCG) Stimulation is a test for whether the testicles produce normal levels of testosterone and Dihydrotestosterone (DHT). Blood tests are drawn for testosterone and DHT, then the hCG is given as an injection. Another blood draw for testosterone and DHT is done 72-96 hours later. (There are other ways to do the hCG stimulation test, this is the most common way we do it). Results are available in 1-2 weeks.


Hypospadias is a malformation that affects the urethral tube and the foreskin on a male’s penis. Three features for hypospadias include: curvature or chordee of the penis; urethral opening on the underside of the penis; and abnormal foreskin appearance. Severe hypospadias may be associated with DSD conditions.

Informed consent is permission given by an individual to proceed with a specific test or procedure, with an understanding of the risks, benefits, limitations, and potential implications of the procedure itself and its results.


A karyotype is an individual’s collection of chromosomes. The term also refers to a laboratory technique that produces an image of an individual’s chromosomes. The karyotype is used to look for abnormal numbers or structures of chromosomes.

Karyotype analysis

A karyotype analysis occurs when a doctor looks at an individual’s cells underneath a microscope and counts the number of chromosomes.  Typically (but not always), a male will have 46 chromosome, including one X and one Y. Typically (but not always), a female will have 46 chromosomes, including two X chromosomes. Sometimes a karyotype can identify some large missing pieces or extra pieces of DNA, but not small pieces.This is a blood test and typically takes 1-2 weeks to perform. It may require a prior authorization from your insurance company before it can be done.

Longitudinal study

A longitudinal study involves studying the same variables or data points over long periods of time.

Luteinizing hormone

Luteinizing Hormone (LH) is a hormone signal from the pituitary gland to the ovaries or testicles, measured by a blood test. Results are available in 24 hours.

Mayer-Rokitansky-Kuster-Hauser syndrome

Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is a disorder that occurs in females and mainly affects the reproductive system. This condition causes the vagina and uterus to be underdeveloped or absent.


Microphallus is a penis that is smaller than typical, usually defined as being below the first percentile in size. A microphallus can be caused by hormone problems before or after birth, because of a genetic syndrome, or for other reasons.

Mosaic DSD

Mosaic DSD is a type of DSD where cells in the human body exhibit more than one type of sex chromosome complement, e.g. XX and XY; X and XY; XY/XXY; X/XX/XY and so on.

MRKH syndrome

See Mayer-Rokitansky-Kuster-Hauser syndrome.


An ovary is one of a pair of female reproductive glands in which the ova, or eggs, are formed. The ovaries are located in the pelvis, one on each side of the uterus.

Ribonucleic acid

See RNA.


Ribonucleic acid (RNA) is one of the two types of nucleic acids found in all cells. The other is deoxyribonucleic acid (DNA). RNA transmits genetic information from DNA to proteins produced by the cell.


Sequencing, or DNA sequencing, is a laboratory technique used to determine the exact sequence of bases (A, C, G, and T) in a DNA molecule. The DNA base sequence carries the information a cell needs to assemble protein and RNA molecules.

Sex chromosomes

Sex chromosomes are types of chromosomes that participate in sex determination. Humans and most other mammals have two sex chromosomes, the X and the Y. Females typically (but not always) have two X chromosomes in their cells, while males typically (but not always) have both X and a Y chromosomes in their cells.

Sex determining Region Y

Sex determining Region Y (SRY) is a gene located on the Y chromosome that makes a protein that causes a fetus to develop as a male.


See Sex determining Region Y.


The testes, or testicles, are the two egg-shaped glands found inside the scrotum. They produce sperm and male hormones.


Testosterone is a male hormone, measured by a blood test. Results are available in 1-2 weeks.

Turner syndrome

Turner syndrome is a genetic disorder that occurs in girls that causes them to be shorter than others and prevents them from undergoing normal puberty as they grow into adulthood.

Undescended testes

Undescended testes is a condition seen in newborns when one or both of the male testes have not passed down into the scrotal sac.


The urethra is the tube that carries urine from the bladder to the outside of the body.


An urethroplasty is a procedure where the urethra is surgically repaired to improve function and genital appearance. Hypospadias is a common condition (occurring in 1/150 males) where the urethral opening is not at the end of the penis and requires a urethroplasty.


A vaginoplasty is a procedure to improve the function and genital appearance. A vaginoplasty may be done when the vagina is connected into a common sinus or channel with the bladder, there is no vaginal opening, or the vagina is narrow.

X chromosome

See Sex chromosomes.

Y chromosome

See Sex chromosomes.