What is the Difference Between Swyer Syndrome and Androgen Insensitivity

The key difference between Swyer syndrome and androgen insensitivity is that Swyer syndrome is a disorder that affects females and is characterized by the failure of sex glands to develop, while androgen insensitivity syndrome is a disorder where a person who is genetically male shows resistance to male hormones called androgens.

Swyer syndrome and androgen insensitivity are two disorders of sex development. Disorders of sex development are a group of conditions involving genes, hormones, and reproductive organs, and genitals. In these disorders, a person’s sex development is different to most other people’s sex development. There is a mismatch between a person’s chromosomes (genetic material) and the appearance of a person’s genitals. It may cause disorders of sex development in infancy, childhood, or adolescence.

1. Overview and Key Difference
2. What is Swyer Syndrome
3. What is Androgen Insensitivity
4. Similarities – Swyer Syndrome and Androgen Insensitivity
5. Swyer Syndrome vs Androgen Insensitivity in Tabular Form
6. Summary – Swyer Syndrome vs Androgen Insensitivity

What is Swyer Syndrome?

Swyer Syndrome and Androgen Insensitivity - Side by Side Comparison

Figure 01: Male and Female Chromosomes

Females with Swyer syndrome have gonadal streaks instead of sex glands. This means ovaries are replaced by functionless (fibrous) scar tissues. As they do not have ovaries, females with Swyer syndrome do not produce sex hormones and do not undergo puberty. This condition is due to a new gene mutation, or it can be inherited in an autosomal dominant, autosomal recessive, X linked or Y linked manner. The Swyer syndrome incidence is recorded at 1 in 80,000 births. The diagnosis can be performed through clinical evaluation, fluorescence in situ hybridization, and molecular genetic testing. Furthermore, Swyer syndrome is usually treated with hormone replacement therapies and surgery.

What is Androgen Insensitivity?

Androgen insensitivity syndrome is a disorder where a person who is genetically a male shows resistance to male hormones called androgens. Therefore, a person affected by androgen insensitivity has some of the physical traits of a woman. Mutation in AR (androgen receptor) gene in the X chromosome causes androgen insensitivity. Complete androgen insensitivity syndrome has the frequency of 2 to 5 per 100,000 people who are genetically male. This condition is inherited as an X-linked recessive pattern. Androgen insensitivity can also be caused due to a new mutation.

Swyer Syndrome vs Androgen Insensitivity in Tabular Form

Figure 02: Androgen Insensitivity

The syndrome is divided into two categories: partial and complete. In partial androgen insensitivity, a person has several male traits. However, in complete androgen insensitivity, the penis and other male body parts fail to develop, and the child looks like a girl. The diagnosis can be made through physical evaluation, biopsying gonads, and molecular genetic testing of androgen receptor genes. Moreover, the treatment plan includes surgery, male breast reduction, hernia repair, hormone replacement therapy (offering testosterone).

What are the Similarities Between Swyer Syndrome and Androgen Insensitivity?

Swyer syndrome and androgen insensitivity are two disorders of sex development.
Both conditions are due to a new gene mutation or inherited gene mutation.
The primary diagnosis of both is via physical evaluation.
Also, both conditions can be treated through hormone replacement therapy.
Both have XY chromosomal make-up.

What is the Difference Between Swyer Syndrome and Androgen Insensitivity?

Swyer syndrome is a disorder that affects females and is characterized by the failure of sex glands to develop. People suffering from this syndrome have functional genitalia and structures, including the vagina, uterus, fallopian tube, but they lack sex glands (ovaries). Androgen insensitivity syndrome is a disorder where a person who is genetically a male shows resistance to androgens. Therefore, a person affected by androgen insensitivity has some of the physical traits of a woman. Thus, this is the key difference between Swyer syndrome and androgen insensitivity. Furthermore, Swyer syndrome is due to mutations in genes such as SRY, NROB1, DHH, WNT4, MAP3K1, while androgen insensitivity is due to a mutation in the gene AR.

The below infographic lists the differences between Swyer syndrome and androgen insensitivity in tabular form for side by side comparison.

Summary – Swyer Syndrome vs Androgen Insensitivity

Disorders of sex development (DSD) are conditions with atypical chromosomal, gonadal, phenotypic sex. This leads to differences in the development of the urogenital tract and different clinical phenotypes. Swyer syndrome and androgen insensitivity are two disorders of sex development. Swyer syndrome affects females. They have functional female organs, including the uterus, fallopian tubes, and vagina. But they don’t have ovaries. Androgen insensitivity syndrome is a disorder where a person who is genetically a male shows resistance to androgens. Therefore, a person affected by androgen insensitivity has some physical traits of a woman. So, this is the summary of the difference between Swyer syndrome and androgen insensitivity.

Reference:

1. “Swyer Syndrome.” Genetic and Rare Diseases Information Center, U.S. Department of Health and Human Services.
2. Gottlieb, Bruce. “Androgen Insensitivity Syndrome.” GeneReviews® [Internet]., U.S. National Library of Medicine, 11 May 2017.