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Mixed Gonadal Dysgenesis

  • Overview text

  • In-Depth

    At Boston Children’s Hospital, we understand that a diagnosis of mixed gonadal dysgensis (MGD) comes with a lot of questions and uncertainty about your child’s sexuality and health. We’ve provided some answers to those questions here, and when you meet with our team of experts, they’ll be able to explain your child’s condition and options in more detail.

     What is MGD?

    Remember that seeking out information is not only necessary but also empowering—it allows you to partner with your child’s care providers to make the best decisions for your child and your family.

    • MGD is a disorder of sexual differentiation in which a chromosomal abnormality causes a child to be born with two different gonads:  an undescended testis and a dysgenetic (malformed) “streak” gonad.
    • MGD is one of the most common disorders of sexual dysfunction and the second most common cause of ambiguous genitalia (sexual organs that aren't well formed or aren't clearly male or female).
    • Most cases of MGD involve an abnormal chromosomal pattern called a mosaic. This means that the child is born with the chromosomes: 46XY, 45XO
    •  This chromosomal abnormality drives the formation of two different gonads: an undescended testicle on one side, and a dysgenetic (improperly developed) gonad on the opposite side.
    • Children with MGD typically have “ambiguous” genitalia, making it difficult to classify them as “boys” or “girls”.
    • The two different gonads can’t produce normal sex hormones, resulting in malformed sex organs.

    Are there any other medical conditions associated with MGD I should be concerned about?

    MGD is usually an isolated issue that doesn’t involve a child’s other organ systems. In very rare cases, children with MGD have an increased risk for certain medical conditions, such as:

    • Denys-Drash syndrome (DDS), which affects a child’s kidneys in addition to malformed sex organs. Children with DDS are predisposed to kidney failure.
    • Wilm’s tumors, a cancerous tumor in the cells of the kidney.


    What causes mixed gonadal dysgenesis (MGD)?

    In a normal pattern of sexual development, chromosomes, gonads, and hormones function like this:

    Chromosomes and Gonads

    • Gonads are the body’s primary sex organs. They form according to a specific chromosomal pattern.
    • Normally, females are born with two X chromosomes (XX) and males are born with one X chromosome and one Y chromosome (XY).
    • As a result of this chromosomal pattern, boys develop gonads called testicles and females develop gonads called ovaries.


    • The primary function of the gonads is producing hormones. Normally, testes produce the male hormone testosterone and ovaries produce the female hormone estrogen.
    • These hormones aid in the formation of sex organs. The testosterone produced from the male testes drive the formation of a phallus. The estrogen produced by female ovaries result in the formation of a vagina.

    Sexual development in children with MGD

    • Children with MGD are born with an abnormal chromosomal pattern called a mosaic: 46 XY, 45 XO
      • Typically, the child has the normal male chromosome XY. The XY chromosome causes a testis to form. In some cases, this testis is undescended.
      • Because XO isn’t a normal chromosomal pattern, it results in the formation of a dysgenetic or malformed gonad. This is referred to as a “streak gonad”
      • The reason why children with MGD aren’t born as “boys” or “girls” is due to the ambiguity of the external genitalia.
    • As a result of having two abnormal gonads, a child with MGD can’t produce normal amounts of sex hormones.

    MGD in the child might look like this:

    • The side with the undescended testis is able to produce testosterone. As a result, a fairly normally scrotum develops.
    • On the side of the streak (improperly developed) gonad, testosterone is not being produced. Instead, female reproductive organs such as a hemi-uterus and fallopian tube are present.

    Signs  & symptoms

     What are the symptoms of MGD?

    • People with MGD are asymptomatic, which means that they present no observable signs of the disorder. MGD can only be detected through medical examination and diagnostic tests.
    • Children with MGD also tend to be shorter than average


    Q: After sex assignment, can a child with MGD lead a fairly normal life as a boy or girl?

    A: Yes. Using surgery to correct malformed genitalia will allow your child to lead a fairly normal life as a boy or a girl. However, he or she may look and feel slightly different from the average child.

    Q: Can my child have children?

    A: No matter which gender they’re raised in, children with MGD are infertile. Those reared as female are infertile because they don’t have an ovary. Males with MGD are infertile because they have an undescended testis, which is dysgenetic (abnormal). While it’s possible that some people with MGD might be able to have children with intensive assisted reproductive techniques, it is unknown.

    Q: Will a child be able to function sexually?

    A: Yes. With the proper surgical correction, children ought to be able to function sexually in a reasonably normal way.

    Q: Are there any complications as children with MGD reach their teen years and go through puberty?

    A: As children with MGD grow older, doctors want to make sure that their hormone production is adequate enough to enter puberty.  A child reared as female will have to take medications containing the female hormone estrogen in order to enter puberty and develop normally. Later on in life, a reassessment of her functioning will be done. This evaluation will be done under anesthesia. As for a male child, the doctors will follow his blood testosterone level to make sure that it remains adequate.

    Q: How can I help my child cope with his condition?

    A:  Support from family and health care providers go a long way in helping your child build healthy self-esteem. Making sure that your child receives psychological counseling is also an important part in maintaining his emotional and mental health. Children’s offers a variety of support services to parents and children.

    If you are having trouble coping with your child’s MGD, we offer many support services that can help you to develop parenting strategies and feel less anxious.

    Q: Will my child need hormone replacement medication? Why?

    A: It depends on the gender of the child.  A male child with a testis that’s functioning well enough to produce male hormones won’t need hormonal therapy. Children reared as females would need hormonal therapy because they don’t have a normal ovary.

    Q: Should my child get corrective genital surgery?

    A: After your child is diagnosed with MGD, you should have a discussion with your family and your child’s doctor about sex assignment. Deciding on a sex assignment depends on the anatomic findings, so it will vary from child to child.

    Corrective surgery is needed most cases because the two gonads do not match up. If you raise the child a male, the female ductal structures on the opposite side would need to be removed. If you raise the child as a female, because the phallus is small and the likelihood is that she would function better as a female, then the testis would need to be removed.

    Questions to ask your doctor

    You will probably have a lot of questions on your mind before meeting with your child’s doctor. At the appointment, it can be easy to be overwhelmed with information and forget the questions you wanted to ask.

    A lot of parents find it helpful to jot down questions beforehand. That way, when you talk to your child’s clinician, you can be sure that all your concerns are addressed. Remember that physicians are open to learning from families too. Attend conferences, read up on updated materials and don’t be afraid to share what you have learned.

    Some questions you might ask include:

    • How do I make a decision about sex assignment?
    • What are the side effects of hormone replacement medication?
    • Which health care providers should my child see and how often?
    • How do I explain MGD to family and friends?
    • When should I tell my child about her MGD? How can I explain in a way he will understand?
    • Should my child get corrective genital surgery?
  • Tests

    The first step in treating a child with mixed gonadal dysgenesis (MGD) is forming an accurate diagnosis. A baby can be diagnosed with MGD soon after birth, when a through physical examination and a series of tests are performed.

    How can doctors tell if my child has MGD?

    MGD is diagnosed based on the presence of the two abnormal gonads: the undescended testis on one side and the streak gonad on the other. During a physical exam, a physician is only able to feel the testis because the streak gonad isn’t something that can be felt.

    If doctors suspect MGD on the initial newborn exam, pediatric specialists in urology and endocrinology will examine your baby right away.

    These tests may include:

    • Pelvic ultrasounds to look for female reproductive structures, such as fallopian tubes and a uterus.
    • Blood tests to determine the level of sex hormones in the blood.
    • Gonadal biopsy to assist in gender assignment
    • Karyotyping, a type of analysis that allows doctors to determine the genetic sex of the baby.
    • Genitogram, a type of test that allows doctors to visualize the outline of the reproductive structures.

    Can MGD be detected prenatally?

    No, MGD is extremely difficult to detect prenatally. Amniocentesis, a procedure doctors use to identify chromosomal disorders in fetuses, isn’t able to accurately detect MGD. This is because a person can have the mosaic 45 XO karyotype involved in MGD and still look normal. A diagnosis of MGD is made based on the presence of the two abnormal gonads, which don’t necessarily result from having the mosaic karyotype.

  • At Boston Children's Hospital, the first step in treating your child's is to determine the appropriate sex for your child. This is done as a partnership between your team of health care providers and your family. This determination will inform the course of treatment. You, as parents, will be involved every step of the way.

    How is a gender assigned?

    Gender assignment is important for treatment purposes as well as the emotional well being of the child as he grows older.  Once you and your child's doctor decide on the appropriate gender for your baby, it's a matter of determining what treatments are most beneficial.

    Typically, the decision on whether to raise a child with MGD as male or female is based on the child's anatomy. If raised male, the child typically makes enough testosterone and wouldn't need additional hormone therapy, which is an additional benefit.

    Raising a child with MGD as female is a bit more complicated. Because she has a testis that's producing testosterone and she doesn't have a normal ovary, surgery will need to be done to remove the testis and the girl will need to be on hormone replacement therapy to receive adequate estrogen.

    What treatments are available?

    The medical treatment options for DSDs may include:


    • Regardless of what sex is assigned to a child, corrective surgery is usually needed to remove or create the appropriate sexual organs.  To avoid any risks associated with anesthesia, corrective surgery usually happens after a child is 6 months old.
    • If the child is raised as male, based on having one decent testis and a decent phallus, it's likely that the female ductal structures on the opposite side would need to be removed.
    • The decision to raise a child as female might be made if the phallus is very small and the doctor believes that the child would function better as a girl. In this case, surgery would be needed to remove the testis

    Hormone replacement therapy (HRT)

    • In terms of lifelong management of MGD, the goal is to keep hormone levels at a normal level.
    • In order to do this, your child may need to take a daily form of cortisol medication, such as:
      • dexamethasone
      • fludrocortisone
      • hydrocortisone

    Will children with MGD receive hormone therapy throughout their whole lives?

    It depends on the gender of the child.  A male child with a testis that's functioning well enough to produce male hormones won't need hormonal therapy. Children reared as females would need hormonal therapy throughout their lives because they don't have a normal ovary.

    How do you determine that my child's hormone levels are normal and he's progressing as he should be?

    For males, blood can be tested to make sure testosterone levels are normal. A male might not need hormone therapy if his testis functions adequately. A doctor will also perform routine clinical examinations to see how a boy is maculinizing. The questions they will want to answer include: Is the penis growing? Are the existing testes growing? Are they developing pubic hair?

    Since females can't produce their own estrogen, doctors will make sure she receives hormone replacement therapy throughout her life. Blood tests can establish that a girl's estrogen levels remain normal.

    Coping and support

    MGD can be emotionally difficult for parents and children alike. Fortunately, there is a lot of support and help available to you.

    • At Boston Children's Hospital's Gender Management Service (GeMS) Clinic we help families deal with the psychosocial issues of raising infants, children, adolescents and young adults with disorders of sexual differentiation (DSDs). Our expert physicians and clinical staff work closely with your child and your family to find the treatment that works best for everyone involved
    • Children's Coping Program helps children who are being treated on an outpatient basis at the hospital—as well as their families—understand and cope with their feelings about:
      • being sick
      • facing uncomfortable procedures
      • handling pain
      • taking medication
      • preparing for surgery
      • changes in friendships and family relations
      • managing school while dealing with an illness
      • grief and loss

    Visit the Behavioral Medicine and Coping Program page or call us at 617-355-6688 to learn more.

    Other sources of support include:

    The Children's For Patients and Families website offers information on the wide array of support services available to families at Children's:

    • Parent to parent: Want to talk with someone whose child has also been diagnosed with MGD? Children's can put you in touch with other families who have been through the same experience you and your child are facing.
    • Faith-based support: A diagnosis of hypospadias may affect how and when your son is circumcised. If this is a religious consideration for you, or if you are simply in need of spiritual support, we will help connect you with the Children's chaplaincy.
    • Social work and mental health professionals: Our social workers and mental health clinicians have helped many other families in your situation. We can offer counseling and assistance with issues such as coping with your child's diagnosis, stresses relating to coping with illness and dealing with financial difficulties.

    For teens

    Adolescence can be stressful—even for physically healthy teens. Having a condition like MGD during adolescence further complicates life for teenagers.

    • Support for teen boys: As a boy with MGD reaches adolescence, he may look and feel different from other males his age. Young Men's Health (YMH) is a website that provides health information for teen boys and young men.
    • Support for teen girls:  Girls with MGD can experience their own set of difficulties when they enter puberty and may exhibit more masculine behavior than other girls their age. The Center For Young Women's Health offers the latest gender-specific information about sexual and emotional health.
    • The Medical Coping Team at Boston Children's Hospital works with teens and their families to help them adjust to the stress caused by chronic illness. Our experienced team of pediatric psychologists, psychiatrists and other mental health professionals provide effective, compassionate evaluation, education, counseling and therapy to help teens cope.


    Parents consider treatment to delay son's puberty
    Norman Spack, MD, Associate Physician in Medicine, speaks with NPR's “All Things Considered” about gender identity treatment on National Public Radio. Read part one of the article on gender identity issues
  • Research & Innovation

    Years ago, babies born with disorders of sexual differentiation (DSD) like mixed gonadal dysgenesis (MGD) were routinely "assigned" a gender by their physicians, and underwent treatment to match that assignment. Today, decision-making is much more individualized and is done in close consultation with the family.

    Today, the medical approach to treating children with DSDs has changed dramatically, thanks in large part to national advocacy groups formed by adult patients.

    The Gender Management Service (GeMS) Clinic at Boston Children's Hospital encourages parents to take part in the decision-making process of how to treat their child’s DSD. We don’t rush families to make important decision, so parents and doctors have adequate tome to chose the best treatment for the child.

    The goals of treatment for MGD are focused on these factors:

    • How are we doing raising these children as male or female?
    • What factors help us best to predict success?
    • What are the most important forms of support we can provide these children and their parents?
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