Pediatric 46-XY Simple Gonadal Hypoplasia Syndrome

Introduction

Brief introduction of 46-XY simple gonadal dysplasia syndrome in children 46-XY simple gonadal dysplasia syndrome (simple46, XYgonadaldigenesissyndrome) is Harnden-Stewart syndrome, also known as Swyer syndrome. The symptoms are characterized by a patient with a female, a cord-like gonad, and no body abnormalities other than the gonads. The karyotype is 46-XY. Only the gonadal dysplasia without the body abnormalities of Turner syndrome. In 1993, Qi Liandi and others pointed out that such cases have a common bearing point, that is, the karyotypes are all 45, X/46XY, and the dysplasia of their underdeveloped gonads have different types, and the clinical manifestations are also different, suggesting that "gonadal hypoplasia" "One, for international adoption. Normally, the early testicular secretion of the male embryos and the decoction of the middle kidney tube, testosterone promotes the development of the renal tube into the male reproductive system, including the attached vas deferens, seminal vesicles, prostate and penis, and the scrotal accessory kidney tube inhibitors. Promote degeneration of the secondary kidney tube. In patients with XY simple gonadal dysplasia, due to chromosome development, the testis is not developed during embryonic stage, and does not secrete ketones and para-neural tube inhibitors, so the renal tube degeneration no longer develops into male genitalia, while the secondary kidney But the tube is developed into a female reproductive system. Sex chromosomes are sex-determining chromosomes. There are one pair. Male is XY, female is XX. Female provides an X chromosome at meiosis. Male provides a Y chromosome. The result is XY or XX after combination, and the probability is equal. . Under normal circumstances, the sex chromosome composition first establishes the gender distinction. After that, the gonadal differentiation, internal and external reproductive organ differentiation are completed throughout the embryonic period, and a complete set of reproductive organ systems is basically established. The fetus male or female, children can be completely recognized at birth. The genital system is still in a naive state. By the time of puberty, with the continuous improvement of brain function and reproductive endocrine system function, sexual function activities are becoming more and more complete, and finally enter sexual maturity. Therefore, in the process of sexual differentiation, any link is damaged, which can affect the normal reproductive function. basic knowledge The proportion of illness: 0.001% Susceptible people: children Mode of infection: non-infectious Complications: malignant tumor

Cause

Pediatric 46-XY simple gonadal dysplasia syndrome etiology

Due to the number of chromosomes and structural abnormalities. It is generally considered to be related to heredity, and its genetic methods are as follows:

1. Multi-gene inheritance : but not yet sure.

2, autosomal dominant inheritance with concealed recessive inheritance or male restriction : normal testicular secretion of the early testosterone in the male embryo and the middle renal tubular inhibitor, testosterone promotes the development of the middle kidney tube into the male reproductive system, including In addition to the vas deferens, seminal vesicles, prostate and penis and scrotum, the renal tubular inhibitory factor promotes the degeneration of the renal tube. In patients with XY simple gonadal dysplasia, due to chromosome development, the testis is not developed during embryonic stage, and does not secrete ketones and para-neural tube inhibitors, so the renal tube degeneration no longer develops into male genitalia, while the secondary kidney But the tube is developed into a female reproductive system.

Sex chromosomes are sex-determining chromosomes. There are one pair. Male is XY, female is XX. Female provides an X chromosome at meiosis. Male provides a Y chromosome. The result is XY or XX after combination, and the probability is equal. . Under normal circumstances, the sex chromosome composition first establishes the gender distinction. After that, the gonadal differentiation, internal and external reproductive organ differentiation are completed throughout the embryonic period, and a complete set of reproductive organ systems is basically established. The fetus male or female, children can be completely recognized at birth. The genital system is still in a naive state. By the time of puberty, with the continuous improvement of brain function and reproductive endocrine system function, sexual function activities are becoming more and more complete, and finally enter sexual maturity. Therefore, in the process of sexual differentiation, any link is damaged, which can affect the normal reproductive function.

Prevention

Pediatric 46-XY simple gonadal dysplasia syndrome prevention

Conduct genetic counseling: For families with a family history: genetic counseling can help adults with selective fertility.

Pre-marital medical examination plays an active role in preventing birth defects. The size of the exercise depends on the examination items and contents, including the family history of the disease, the personal medical history of the individual, and the consultation of genetic diseases. Systemic birth defect screening is required during antenatal care during pregnancy, including regular ultrasound, serological screening, and chromosomal examination.

Complication

Pediatric 46-XY simple gonadal dysplasia syndrome complications Complications malignant tumor

The second sexual characteristics are poorly developed and can cause gonadal tumors. The patient with this disease contains the Y chromosome, and it is prone to malignant tumors with testicular hypoplasia.

Symptom

Pediatric 46-XY simple gonadal dysplasia syndrome symptoms common symptoms no menstrual cramps clitoris hypertrophic gonadal dysplasia vulva childish secondary characteristics change breast or nipple is not developed

Adolescent performance:

After entering the age of puberty, the child developed secondary or lack of secondary sexual characteristics, no menstrual cramps, and the external genitalia continued to be naive. The child has normal growth and development, and there is no congenital malformation other than reproductive line. XY simple gonadal dysplasia may have a number of androgen in the residual cord-like gonadal tissue, and some male hormones may occur after puberty, such as Clitoris hypertrophy and so on. In addition, the residual cord-like gonadal tissue of XY simple gonadal dysgenesis is prone to neoplastic lesions, and its mechanism is unknown.

Performance after adulthood:

The body shape is castrated, the nipple is not developed, there is uterus, vagina, but all are stunted, there is no normal development of follicles, so it is impossible to pass, ovulate and conceive. The patient's appearance is female, the second sexual characteristics are poorly developed, the clitoris can be larger, the intelligence is normal, not short, and there is no neck sputum.

Clinical features of only gonadal dysplasia, women with simple puberty and sexual development should think of this disease.

Examine

Examination of 46-XY simple gonadal dysplasia syndrome in children

Hormone test: patients with elevated blood or urine gonadotropins, while blood levels of sex hormones decreased, urine estrogen and 17-ketosteroids also decreased. Karyotype analysis: refers to the general term for all measurable phenotypic characteristics of somatic chromosomes under optical microscopy. The disease is 46, XY. Laparoscopy: visible residual uterus of the hypoplasia and two gray-white reproductive cords that replace the ovary.

Histological examination: Similar to Turner's syndrome, there are no follicles in the residual reproductive cord tissue.

Exploratory laparotomy: The ovaries are small, and the gonads are strip-like, about 2~3cm long and 0.5cm wide. Observed under the microscope, the cortex has a thin cortex, medulla and door. The cortex is a typical ovarian stroma, the cells are long wavy, and there are portal cells and ovarian nets in the portal. The ovary of this embryo had a normal number of primordial follicles 12 weeks before the embryo. As the fetus grows, the number of primordial follicles gradually decreases, and there is almost no adulthood.

B-ultrasound examination of the reproductive system: understanding the uterus, attachments, vagina, prostate, testicles, etc.

Diagnosis

Diagnosis and diagnosis of 46-XY simple gonadal dysplasia syndrome in children

diagnosis

clinical diagnosis

46, XY simple gonadal dysplasia is common manifestation is that the testis is not developed, bilateral gonads are strip-like, the middle kidney tube fails to develop into the male reproductive system, and the secondary renal tube develops into the fallopian tube, uterus and part of the vagina, external genitalia Female performance.

Inspection diagnosis

Laboratory karyotype examination, karyotype (46, XX or 46, XY), sex hormone and gonadotropin testing, laparoscopy and histological examination, have a diagnostic value for this disease.

Differential diagnosis

In the human body, the control of puberty is regulated by the hypothalamic-pituitary-gonadal axis. Any cause such as congenital diseases, trauma, surgery, infection, cancer, malnutrition or excess, living habits and occupations can cause gonads, including precocious puberty, sexual naivety, and sexual differentiation.

Turner syndrome: The patient has female performance, the second sexual characteristics are not developed, and the shortness, neck, elbow valgus, and gonad are strip-like. A chromosome check revealed that there is only one X chromosome. Therefore, it is called congenital gonadal dysplasia, no gonad of Y chromosome, only developed into ovary. The main differences are:

1 In addition to sexual characteristics and genital development, the patient is not accompanied by other manifestations such as short stature, multiple deformities and intelligent backwardness;

The majority of 2 karyotypes were 46, XY, etc.

Testicular feminization: Testicular feminization syndrome patients have testis, but the phenotype of the body and external genitalia is female, so it is called testicular feminization syndrome. The karyotype is 46XY, and the HY antigen is positive. There are well-developed interstitial cells in the testis, and the androgen secreted can reach normal levels, but there is no male reproductive duct, the external genitalia is female, and there is a female body.

Mayer-Rokitansky-Küster syndrome: caused by degenerative renal tube development disorders, mainly characterized by congenital absence of vagina, primordial uterus, female secondary sexual characteristics, external genitalia, fallopian tubes, ovaries are normal.

XX simple gonadal dysplasia: its performance is similar to this disease. Because the above two diseases are all hypogonadal hypoplasia, there is no normal development of follicles, so they can not pass, ovulate and conceive. True hermaphroditism: There are two gonads of ovary and testis in the patient, or there are two kinds of gonads in the ovary and testis, so it is called hermaphroditism.

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