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Disorders of sex development

Medical conditions involving the development of the reproductive system

  • 27 min read
  • 8 chapters

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Through Chromosome, Gene and Endocrinology

DSDs are subdivided into groups in which the labels generally emphasize the karyotype's role in diagnosis: 46,XX; 46,XY; sex chromosome; XX, sex reversal; ovotesticular disorder; and XY, sex reversal.

In the cases when a baby is born with an atypical anatomical sex, families often experience confusion and distress. Sexual and psychological development are influenced by numerous factors that include, but are not limited to, gender differences in brain structure, genes associated with sexual development, prenatal androgen exposure, interactions with family, and cultural and societal factors. Because of the complex and multifaceted factors involved, communication and psychosexual support are important.

A team of experts, or patient support groups, are usually recommended for cases related to sexual anomalies. This team of experts are usually derived from a variety of disciplines including pediatricians, neonatologists, pediatric urologists, pediatric general surgeons, endocrinologists, geneticists, radiologists, psychologists and social workers. These professionals are capable of providing first line (prenatal) and second line diagnostic (postnatal) tests to examine and diagnose sexual anomalies.

Overview

DSDs are defined as "any problem noted at birth where the genitalia are atypical in relation to the chromosomes or gonads". There are several types of DSDs, and their effect on the external and internal reproductive organs varies greatly.

A frequently used, casual social adjective for people with DSDs is "intersex". Urologists were concerned that terms like intersex, hermaphrodite, and pseudohermaphrodite were confusing and pejorative with respect to humans. This led to the Chicago Consensus in 2005, recommending a new terminology based on the umbrella term disorders of sex development. However, intersex people have continued to prefer the term "intersex" over "DSD" by large margins. Other than disorders of sex development, another term is congenital conditions of sex development (CCSD). Since 2006, people who were previously incorrectly categorized as hermaphrodites are now labelled as having ovotesticular syndrome.

DSDs are divided into the following categories, emphasizing the karyotype's role in diagnosis:

  • 46,XX DSD: Genetic Female Sex Chromosomes. Mainly virilized females as a result of congenital adrenal hyperplasia (CAH) and girls with aberrant ovarian development.
  • 46,XY DSD: Genetic Male Sex Chromosomes. Individuals with abnormal testicular differentiation, defects in testosterone biosynthesis, and impaired testosterone action.
  • Sex chromosome DSD: patients with sex chromosome aneuploidy or mosaic sex karyotypes. This includes patients with Turner Syndrome (45,X or 45,X0) and Klinefelter Syndrome (47,XXY) even though they do not generally present with atypical genitals.
  • XX, Sex reversal: consist of two groups of patients with male phenotypes, the first with translocated Sex-determining region Y protein (SRY) and the second with no SRY gene.
  • Ovotesticular disorder: patients having both ovarian and testicular tissue. In some cases the ovarian tissue is functional.
  • XY, Sex reversal: patients with female phenotypes where duplication in the Xp21.2 region of the X chromosome that contains the NR0B1 (DAX1) gene is associated with XY sex reversal.

Genital anatomy

The penis (males) and clitoris (females) have a common origin, both arising from an embryonic structure called the primordial phallus. In typical males, the urethra is located at the tip of the penis, while in typical females the urethra is located below the base of the clitoris. It is also possible to have a urethral opening located along the shaft; this condition is known as hypospadias.

Management of DSDs

Due to the significant and life-long impacts that DSDs can have on patients and their families, it is widely accepted that children with DSDs should be managed by an experienced multidisciplinary team. Health care providers generally agree that children with DSDs should be notified early.

Appropriate and conservative medical intervention and age-appropriate child involvement in the treatment plan contribute greatly to successful outcomes for the entire range of DSDs.

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