What Is Pseudohermaphroditism?
Pseudohermaphroditism is a disorder in which a person has a matching chromosomal and gonadal (ovary or testes) sex but mismatching external genitals. In female pseudohermaphroditism, an individual with ovaries will have external genitalia resembling the male. Male pseudohermaphroditism refers to individuals having testes as gonads, but the secondary sexual characteristics or external genitals are similar to those of a female.
What Is Male Pseudohermaphroditism?
Male pseudohermaphroditism is a sex differentiation disorder in which the gonads are testes, but the external genitalia and secondary sexual characteristics are incompletely differentiated. This condition is caused by a failure in the sequential development of testes in the embryonic phase. It is a rare disorder. The gonads in a male pseudohermaphrodite are either streak gonads (underdeveloped gonads) or testes.
Male pseudohermaphroditism is males having the chromosomal configuration of 45, XY. They, however, develop female sexual characteristics and identities. These people have testes, but their genital canals and external genitalia resemble those of a female. In some individuals, secondary sexual characteristics may never appear, whereas others may exhibit a completely feminized appearance.
What Are the Causes of Male Pseudohermaphroditism?
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Genetic Disorder- Male pseudohermaphroditism is a rare condition. It usually occurs due to an autosomal recessive genetic disorder (a disorder that must be genetically inherited from both the parents of an affected individual to express itself).
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Leydig Cell Failure- There are several specific defects responsible for leading to the development of feminine characteristics in genetic males. Each specific defect results in a loss of masculinizing effects on body tissues. In rare instances, Leydig cells (cells of the testes responsible for secreting testosterone hormone in males) are completely missing or considerably decreased in number. The condition may develop due to a possible defect in the receptors for luteinizing hormone (LH). Therefore, very small amounts of testosterone are synthesized.
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Androgen Insensitivity Syndrome- In some individuals, the tissue receptors for male hormones are completely absent or reduced, creating a spectrum of disorders characterized by partial to complete resistance to androgens (male hormones).
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Complete testicular feminization syndrome is one of the most striking examples of androgen resistance. In this syndrome, the affected individuals are born with female external genitalia and a vagina with no cervix or uterus. Despite testes situated within the abdomen, these individuals grow into full-fledged females with normal breasts and scanty or fully absent axillary and pubic hair. These individuals have a strong sexual orientation towards females but do not menstruate. Their hormonal defects are quite dramatic and predictable.
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Testosterone Synthesis Defects- There is no inhibition of luteinizing hormone secretion with a subsequent loss of the pituitary androgen receptors. The luteinizing hormone concentrations are high in the serum, stimulating Leydig cells and causing high testosterone concentrations in the serum. However, the increased quantities of testosterone hormone are converted to estrogen in the peripheral tissues. This leads to increased concentrations of the estrogen hormone in the serum of the males.
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5- Alpha Reductase Deficiency- In some variants, the lesion occurs as a loss of 5-alpha-reductase, an essential enzyme for converting testosterone hormone to dihydrotestosterone, a more potent hormone. In this syndrome, genetic males have external genitalia similar to female genitals with a large clitoris. This occurs due to the absence of the testosterone hormone responsible for direct fetal development toward a healthy male configuration. These individuals are usually brought up as females, but at maturity (puberty), a rise in testosterone levels can lead to masculinization. This leads to the complicated transition phase of the psychosocial behavior of a premature female to that of a mature male.
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Congenital Anorchia- In a few fetuses, vanishing testes syndrome (the testes regress and disappear) is observed. If this condition occurs during the initial phase of pregnancy before the male hormone-induced differentiation toward male genitals, the newborn baby will be born with female external genitalia. During the crucial period of eight to ten weeks from conception, the newly born baby is born with ambiguous genitalia (the genitals of an infant appear indistinct and do not appear clearly as male or female genitals). In contrast, if they disappear after the crucial period, the infant is born as a male but without having any testes. This condition is called anorchia.
What Are the Clinical Features of Male Pseudohermaphroditism?
Male pseudohermaphroditism is a rare sexual differentiation disorder characterized by bilateral testicular dysgenesis syndrome or streak testis (aplasia resulting in an inability to secrete male androgens), persistent Mullerian structures (structures that are present in a girl fetus that will eventually develop into reproductive organs of a female), and cryptorchidism (a disorder in which either one or both the testes fail to descend from the abdomen into the scrotal sac).
How Is the Diagnosis of Male Pseudohermaphroditism Made?
The diagnosis of male pseudohermaphroditism can be established by performing a human chorionic gonadotropin hormone stimulation test (HCG stimulation test).
What Is Human Chorionic Gonadotropin Hormone Stimulation Test (HCG Stimulation Test)?
The HCG stimulation test is usually done in infants with indistinct genitalia and palpable testes or ovaries. It is also performed in males having delayed puberty or undescended testes in the scrotum to confirm the presence of potent testicular tissue.
The principle behind this test is that the human chorionic gonadotropin hormone is a double polypeptide hormone. It shares a common subunit with the luteinizing hormone. It thereby stimulates the interstitial Leydig cells in the testes to produce androgens via the luteinizing receptors. One injection of human chorionic gonadotropin hormone is sufficient to produce a progressive but slow rise in testosterone hormone in serum for the next 72 to 120 hours since it has a half-life of 2.5 days.
What Is the Treatment of Male Pseudohermaphroditism?
Treatment should be exclusively individualized. It depends from person to person. In many cases, gender identity (self-conception as a man or woman) is usually established by the age of two years, and changes in sexual identity should be monitored carefully after that. Testes present intra-abdominally should be surgically removed to reduce the risk of tumor formation. The affected individual can be treated with sex hormones at an appropriate time.
Conclusion
Patients suffering from male pseudohermaphroditism have a chromosomal karyotype of 46 XY and may exhibit female characteristics. The responsiveness of the genital organs usually influences the treatment of this condition to male hormones and the surgical complexity of technique-sensitive reconstructive procedures. The molecular genetics of this disorder should be studied in detail in the near future, and measures to prevent these genetically determined malformations should be elucidated.
