Reifenstein syndrome is one of a group of diseases in which the body is unable to respond appropriately to the male sex hormones (androgens), which include testosterone.

The syndrome is passed down through families (inherited) and causes underdevelopment of the male reproductive tract.

In this syndrome, a problem with a gene causes cells to be less responsive to male hormones called androgens. It is also called Partial Androgen Insensitivity Syndrome.

As a male baby grows in the womb, male hormones (androgens) are made. As a result, male sexual organs develop. However, sometimes there is a change in the gene that helps make a protein (receptor) that tells the body how to use androgen properly. If androgen cannot be processed normally because of a defect in this protein, problems with the development of the male sex organs occur. At birth, this may result in confusion over the sex of the baby due to ambiguous genitalia.

The disease is inherited in an X-linked recessive manner, which means that women are not affected but may carry the gene. Males who inherit the gene from their mothers will have the condition. There is a 50% chance that a male child of a mother with the gene will be affected. Family history is important in determining risk factors.

The syndrome is estimated to affect 1 in 99,000 people.

Symptoms include:

• Sexual dysfunction in males and infertility
• Abnormal male genitals
  • Undescended testes
  • Small scrotum, with a line down the middle (bifid) or incompletely closed
  • small penis
  • Hypospadias (the urethra exits the body on the side of the penis, not the tip)
• Breast development in males at time of puberty
• Decreased body hair and beard, but normal pubic and armpit hair

The doctor will perform a physical exam. The male may have:

• Decreased or absent vas deferens (the tubes through which sperm exit the testes)
• Partial development of female sex organs

Tests may include:

• Blood tests to check for high levels of testosterone and luteinizing hormone
• Sperm count
• Testicular biopsy
• Genetic tests to look for defects in the androgen receptor gene

Early and continuous testosterone treatment may improve the chance that a boy will grow up to be fertile.

Androgen Insensitivity Syndrome Support Group (AISSG) -- www.medhelp.org/www/ais/

Intersex Society of North America (ISNA) -- www.isna.org

Androgens are most important during early development in the womb. Those with Reifenstein syndrome can have a normal lifespan and be totally healthy, with the exception of infertility and possible psychological problems related to gender identity.

In the most severe cases, psychological and emotional problems may occur in boys with outer female genitalia or an extremely small penis. Management of these patients is very complex.

Genital surgery should be postponed until the patient can make an informed choice.

• Infertility and failure to develop normal male gonads/genitals.
• Breast development in men can be a cosmetic concern.
• Psychological problems like depression may occur.

Call your health care provider if you, your son, or a male family member has infertility or incomplete development of male external organs, despite high blood testosterone. Genetic testing and counseling is available if there is a strong suspicion that this disease is present.

Prenatal testing is available. People with a family history of these conditions should consider genetic counseling. Testosterone treatment that is started early may prevent some infertility.