Anomalies differentiation of gonads

August 12, 2017 17:51 | Genetic Diseases

At the heart malformations differentiation of gonads (sexual glands) are quantitative or qualitative abnormalities of sex chromosomes, leading to disruption of the formation of the primary tabs gonads, of which later formed the ovaries in women and testes in men.This process is carried out on the 6-10 th week of fetal development, and requires a full set of sex chromosomes (XX for girls and XY in males).

«clean» gonadal agenesis (set of sex chromosomes XX). The disease is characterized by the structure of the female external and internal sex organs.Gonads are presented in the form of connective tissue strands (Streck).The alleged cause of the disease is a mutation of a gene required for the normal development and functioning of the ovary.In the period of puberty do not develop breasts, has primary amenorrhea (absence of menstruation).In the study of hormonal abnormalities detected characteristic in the form of low levels of female sex hormones.The disease is often associated with neurological disorders

: deaf-mutism, impaired motor coordination.Choosing a female is not in doubt.During puberty these women the therapy hormonal therapy.The literature contains descriptions of familial cases of the disease.

«clean» gonadal agenesis (set of XY sex chromosomes) .It is characterized by feminine structure of the external and internal genitalia, the presence of gonads as Streck (fibrous bands), sexual underdevelopment in the period of puberty.Sometimes there is poor conversion of the external genitalia in a hypertrophied clitoris.The disease is often associated with neurological and renal congenital anomalies.There is a high risk of developing cancer of the sex glands at puberty.Surgical removal strekovyh gonads (sexual glands) is a must in this disease.In adolescence (puberty) therapy is performed by female sex hormones.

Turner Syndrome Shereshevskogo- (gonadal dysgenesis) .In most cases, it is characterized by monosomy for the X chromosome (45, X0), at least - the loss portion of the X chromosome, or a structural anomaly.In Turner's syndrome there are other options for a set of sex chromosomes: 45, H0,45, XO / 46, XX, 46, XX / loss portion of the X chromosome, 46, XX / isochromosome, ring X chromosome, 45, the XO /46, XY.X-chromosome anomaly is likely to disrupt genes proyavlyaemosti controlling ovarian development and function, resulting in place ovarian arrangement formed fibrous strands (strekovye gonads).Furthermore, suffer genes controlling the processes of growth and differentiation of normal cells in the body, leading to lower final growth and development of many congenital malformations.

disease is one of the most common causes of hypogonadism (underdevelopment sexual glands) in girls.In the neonatal period are typical manifestations of reduced growth and birth weight, swelling of the lower legs and feet.The disease is caused by monosomy for the X chromosome and ring X chromosome, is characterized by severe external features: shortened neck, wing-folds of the neck, the semilunar fold of skin at the inner corner of the eye, "a Gothic sky", shortening of metacarpals and many other possible cardiovascular malformations.vascular, renal anomalies (renal ptosis, its rotation).Distinct growth retardation in children with Turner's syndrome is marked by 6-7 years, progressing in the future due to lack of growth jump at puberty that occurs in healthy children, and the final height of these children is usually not more than 140-150 cm.The development of skeletal slightly behind the child's age.Growth hormone is not broken, but in puberty as a result of the lack of sex hormones of growth hormone can be reduced.During puberty in 92% of children are secondary sexual characteristics are completely absent, there is a primary amenorrhoea (complete absence of menstruation).Secondary body hair develops in 12-13 years due to the effects of the male sex hormones produced by the adrenal glands.In rare cases it may occur spontaneously during puberty and menstrual function, which quickly exhausted.

Identification of the disease is based on carrying out karyotype (chromosome study set) and identify monosomy for the X chromosome syndrome or other possible options.Given the high incidence of Turner syndrome, the study sets of chromosomes is carried out for all the girls who have expressed stunted growth and lack of secondary sexual characteristics to the beginning of puberty.

the treatment of children with Turner's syndrome solve two main problems: the correction of short stature and underdeveloped gonads.Currently, there is no uniform method of correction of growth in this disease.Perhaps the use of anabolic steroids drugs that stimulate metabolism and thereby promote the growth of the child (oxandrolone 0.05-0.1 mg / kg per day, retabolil 1.0 mg per month).The increasingly widespread use of drugs is growth hormone in a dose of from 0.5 to 1.8 IU / kg per week.Perhaps the combined use of growth hormone and anabolic steroids or estrogen (female sex hormones).Substitution therapy sex hormones begins upon reaching the 12-13-year-olds.After reaching effect (development of mammary glands, development of sexual glands of female type) is assigned to the same cyclic therapy drugs that are used for hormone replacement therapy.

Mixed testicular dysgenesis (asymmetrical gonadal dysgenesis). This disease is characterized by the formation of asymmetrical gonads (gonads), wherein there Streck on one side and the opposite side of the testes.The majority of people identify chromosomal abnormalities in the form of 45, XO / 46, XY.At a set of chromosomes 46, XY possible structural anomalies of the male Y-chromosome.

external genitalia at birth, bisexual, t. E. Resemble the structure and female and male genital organs.The penis is formed well enough.All persons with the disease have an internal female genitalia: uterus, uterine (fallopian) tube, formed largely by Streck (degeneration of the sexual glands in fibrous cord).At external examination may be noted are the same traits that are characteristic of Turner's syndrome.During the period of sexual development may satisfactory formation of secondary male sexual characteristics saved owing androgen (male sex hormones generator - androgens) testicular function.Possible full adaptation to the male sex, after appropriate surgical correction of the external genitalia and the compulsory removal of pathologically altered gonads in connection with the danger of her tumor.

Bilateral testicular dysgenesis (false male hermaphroditism, rudimentary testes syndrome) characterized by bilateral hypoplasia of the testicles with their insufficient function bland male development of the external genitalia and female sexual organs.A set of sex chromosomes in this disease is no different from a normal male (XY), structural abnormalities of male Y-chromosome are often combined with congenital anomalies of the kidney and Wilms tumor.During puberty manifested all the characteristic signs of hermaphroditism.There is a high risk of developing cancer of the sex glands.The lack of functional ability of the testes to produce testosterone (male sex hormone) dictates the choice of a female, which is achieved by carrying out the correction of the external genitalia with the formation of the female external genitalia and mandatory removal of immature male gonads.During puberty spend replacement therapy female sex hormones.

true hermaphroditism (bisexual gonad syndrome) - an extremely rare disease in which the individual elements are available and ovarian and testicular tissue.To identify this form of hermaphroditism is possible only on the basis of morphological study of gonads.In true hermaphroditism elements of the feminine and masculine fabrics may be in one of the sex glands mixed or separately and can be located in two separate gonads (ie, one iron in this case is represented by an egg, and the other -.. The ovary).

reasons for this state is currently not clear.The most common set of sex chromosomes corresponds to a normal female (46, XX), at least - the male sex (46, XY).At the present time we are more likely to think about the possibility of transferring the male portion of the Y-chromosome in the female X chromosome.The alleged cause of mosaicism 46, XX / 46, XY considered as double fertilization of the same ovum, followed by the formation of bisexual gonads (sexual glands).

external genitalia in this disease have a bisexual structure, but rarely can meet persons with normal male or female structure of the external genitalia.In almost all cases of true hermaphroditism internal genitals retain female type (the presence of the uterus, fallopian tubes, vagina).During puberty symptoms can omuzhestvleniya (clitoral enlargement, male pattern hair distribution, rough voice) or the development of female secondary sexual characteristics (breast enlargement, the beginning of menstruation), depending on the degree of functional activity of the gonads.

Choosing baby's sex depends on the degree omuzhestvleniya external genitalia and the functional activity of the testis and ovary.Diseased tissue gonads subject to mandatory removal due to the danger of malignancy.In the case of a female selecting remove testicular tissue and produce the plastic of the external genitalia of female type.Choosing a male is recommended only with full confidence in the presence of a full testicular tissue.Hormone therapy is carried out in the period of puberty in accordance with the selected floor in cases where gonads removed completely.The remaining ovarian tissue or eggs are usually fully provides the body with sex hormones.