Congenital Disorders of Sexual Differentiation

Congenital disorders of sexual differentiation

Pathogenesis. The sex of the gonad is determined genetically and depends on the combination of sex chromosomes; two X chromosomes determine the female sex, and the combination of X and Y chromosomes determines the male sex. For normal function of the gonads, not only a set of chromosomes XX and XY is required, but also a complete set of genes.

Disturbances in the set of chromosomes that arise from nondisjunction of sex chromosomes, the loss of one chromosome or changes in the structure of chromosomes lead to diseases characterized by impaired sexual differentiation. In these cases, the tissue of the reproductive gland is not capable of normal secretion of sex hormones and the development of male or female principles is determined by the elements of the reproductive tissue that form the gonad.

Symptoms, course. Agonadism (congenital absence of the gonads) and gonadal dysgenesis are observed (individual structural elements of the gonads can be detected). The symptoms of various clinical forms of gonadal dysgenesis are varied.

Shereshevsky-Turner syndrome is easily diagnosed by external signs: absence of secondary sexual characteristics, underdevelopment of the mammary glands, external genitalia, short stature, short neck with pterygoid folds, often skeletal abnormalities - valgus deviation of the elbow and knee joints, syndactyly, vertebral deformity, ptosis, high palate, disorders of the cardiovascular system - heart defects and large vessels. Sex chromatin is negative, the karyotype is often 46, XY.

It is more difficult to diagnose “pure gonadal dysgenesis”, in which there are no somatic anomalies characteristic of Shereshevsky-Turner syndrome. The results of the examination of the internal genital organs are of great importance: there are no gonads; rudimentary uterus, tubes, vagina. Sex chromatin is negative, chromosome set is 46, XY.

With Shereshevsky–Turner syndrome and “pure gonadal dysgenesis,” in some cases, signs of masculinization may be observed: clitoral hypertrophy, virile hair growth.

One form of gonadal dysgenesis is ovarian dysgenesis. Main symptoms: absence of menstruation, underdevelopment of secondary sexual characteristics. Testicular dysgenesis: the presence of internal female genital organs in the absence of ovarian elements, the external genitalia are bisexual. Negative sex chromatin, karyotype 46, XY.

Testicular feminization (false male hermaphroditism) – development of the external genitalia and secondary sexual characteristics according to the female type, the presence of male gonads, absence of the uterus, negative sex chromatin, karyotype 46, XY. In some cases (with an incomplete form), signs of masculinization may be revealed: insufficient development of the mammary glands, a rough voice, hypertrophy of the clitoris.

Klinefelter's syndrome - gynecomastia, eunuchoid body proportions, underdevelopment of secondary sexual characteristics, underdevelopment of the testicles with normal penis size, azoospermia, decreased potency. Sex chromatin is positive, karyotype 47, XXY.

True hermaphroditism is the presence in an individual of functioning gonadal tissue of both sexes and, as a result, female and male sexual characteristics. When studying a karyotype, it is most often defined as XX/XY.

Treatment. If necessary, gender correction is carried out taking into account psychosexual orientation and the anatomical and functional capabilities of the genital area. Replacement therapy with sex hormones depending on the chosen sex: estradiol dipropionate, ethinyl estradiol (microfollin) are used to enhance feminization, and testosterone preparations are used for masculinization.