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.

As a male baby grows in the womb, male hormones (androgens) are made. This leads to the development of male sex organs.

In this condition, there is a change in the gene that helps the body recognize and use male hormones properly. This leads to problems with the development of the male sex organs. At birth, the baby may have ambiguous genitals, which leads to confusion over the baby's sex.

The syndrome is passed down through families (inherited). 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. Every female child has a 50% chance of carrying the gene. Family history is important in determining risk factors.

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

• Abnormal male genitals
  • Hypospadias
  • Small penis
  • Small scrotum, with a line down the middle (bifid) or incompletely closed
  • Undescended testicles
• Breast development in males at time of puberty
• Decreased body hair and beard, but normal pubic and armpit hair
• Sexual dysfunction in males and infertility

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

• Partially developed female sex organs
• Small or absent vas deferens (the tubes through which sperm exit the testes)

Tests may include:

• Blood tests
• Genetic tests
• Sperm count
• Testicular biopsy

Treatment with testosterone may improve the chance that a boy will be able to have children when he grows up.

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, but they may be infertile and have psychological problems related to gender identity.

In the most severe cases, boys with outer female genitals or an extremely small penis may have psychological and emotional problems.

Genital surgery should be postponed until the patient is old enough to make the decision.

• Breast development in men
• Infertility and failure to develop normal male genitals
• Psychological problems, such as depression

Call your health care provider if you, your son, or a male family member has infertility or incomplete development of male genitals. Genetic testing and counseling are always recommended if this disease is suspected.

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.