true hermaphroditism
Introduction
Introduction to true hermaphroditism Sexual malformation is a congenital genital malformation with secondary sexual abnormalities. There are many types and manifestations of hermaphroditism. It is very important to determine the essence of gender malformation at an early stage and timely treatment. The hermaphroditism can be divided into true hermaphroditism and pseudohermaphroditism. The true hermaphroditism is the presence of ovarian and testicular tissues in the body. The karyotype can be normal male, female or chimeric. The reproductive duct and external genitalia are often Sexual deformity. The true amphoteric malformation gland must be intact, that is, the testicles must have a normal structure, with signs of seminiferous tubules, interstitial cells, and germ cells; the ovaries must have various follicles and have egg cell growth, as for only the ovaries or The residual tissue of the testes does not belong to the true hermaphroditism. basic knowledge The proportion of illness: the incidence is extremely low, the disease is rare, about 0.0001% - 0.0003% Susceptible people: no specific population Mode of infection: non-infectious Complications: hypospadias inguinal hernia cryptorchidism
Cause
Cause of true hermaphroditism
Chromosomal factors (50%):
The cause of true hermaphroditism may be: 1 monozygotic chromosome mosaic, which is caused by meiosis or mitosis error; 2 non-monozygous chromosome mosaic, which is often the result of fusion or two fertilization of two fertilized eggs; 3Y The chromosome translocates to the X chromosome.
Gene mutation (30%):
A gene mutation is a genetic mutation caused by the addition, deletion or replacement of a base pair in a DNA molecule. A structural change that can be inherited within a gene. Also known as point mutations, usually cause a certain phenotypic change. Autosomal mutant genes, the inheritance of familial patients is autosomal recessive or dominant inheritance.
Pathogenesis:
For autosomal recessive inheritance, true karyotype is 46, XX is 60%, karyotype is 46, XY is 20%, karyotype is chimera 46, XX/46, XY is about 20%, in karyotype In the gene organization of 46, XX, the Y chromosome was not found with the Y-specific DNA probe, so the pathogenesis of YX or Yautochromic translocation or transchromosomal chimerism could not be explained, and controllability has been demonstrated. The genes for development and differentiation may be located on the autosomes. It has been reported that 46, XX karyotypes are positive for both HY, external genital malformations, gonads are ovarian testis, but the sex is a man and a woman, which is believed to be transmitted by the father. Autosomal dominant inheritance.
The cell culture of the testis of XX true hermaphroditism was found to be positive for HY antigen, while the culture from the ovary portion was negative, suggesting that the egg testis originated from a HY-positive/HY-positive chimeric primordium.
The etiology of true hermaphroditism karyotype 46, XY remains to be further studied, and its pathogenesis is similar to 46, XY incomplete gonadal dysplasia, in the early stages of testicular development, genetic variation related to testicular development in areas such as genital warts, and One region retains the tendency to differentiate into the ovary. Due to the lack of double X chromosome, the primordial follicles in the ovarian tissue accelerate to differentiate. If some follicles remain, this condition is called true bisexual. If only the ovarian matrix remains, it is called gonad development. Incomplete, therefore, ovarian plateau and gonadal dysplasia are likely to be different manifestations in the same process.
Prevention
True hermaphroditism prevention
There are two main causes of fetal malformation. One is genetic defects that cause fetal malformations. Those who are close relatives or have family genetic diseases are most likely to have such problems. The other is non-hereditary gene defects that cause fetal malformations. It is often due to the neglect of teratogenic factors during pregnancy. Therefore, pregnant women should strengthen pregnancy care during pregnancy, quit smoking and alcohol, and prevent radiation.
Complication
True hermaphroditism complications Complications hypospadias inguinal hernia
Often combined with hypospadias or penile ligament, half of patients with inguinal hernia and cryptorchidism.
Symptom
True hermaphroditism symptoms common symptoms hermaphroditism breast hypertrophy masculine
When the patient is born, the genitals are difficult to distinguish between men and women, but they tend to be male. About 3/4 of the children are treated as boys. The scrotal dysplasia is like the labia majora. Most of the gonads can be found in the groin or scrotum. Generally, female secondary sexual characteristics, such as breast hypertrophy, female body shape, pubic hair is female-like distribution, may have menstrual cramps, because any karyotype of true hermaphroditism has ovarian tissue, and the structure of the ovary is relatively perfect, so Most of the ovaries with true amphoteric malformation can secrete estrogen during development, and also secrete progesterone when ovulating, so female secondary sexual characteristics can occur, but the development of the breast is late, the patient has uterus and vagina, and the vaginal opening is in the urine. Genital sinus, a common uterine developmental disorder is dysplasia and lack of the cervix.
If the gonad is the ovary, then the microscope is generally normal, and the testes are not produced under the microscope, so the patient can have normal ovarian function, very few patients can even get pregnant, the egg testis is the most common gonad abnormality, about half of the ovarian testis In the normal ovary position, the other half is in the groin or in the scrotum. The location of the egg testis is related to its composition. The greater the proportion of testicular tissue, the easier it is to enter the groin or scrotum. The genital tube on the ovary side is always the fallopian tube. The genital tube on one side of the testicle is a vas deferens. As for the genital tube on the side of the egg test, it can be either a fallopian tube or a vas deferens. This is related to the composition of the ovary and testicular tissue, and it is common to have a fallopian tube.
There are 3 types of true hermaphroditism:
1. One side is the ovary and the other side is the testicle, which is called unilateral true hermaphroditism. This type accounts for 40%.
2. Both sides are ovarian testis (that is, both ovarian tissue and testicular tissue in one gonad), and there is fibrous tissue between ovarian tissue and testicular tissue, called bilateral true hermaphroditism, which accounts for 20%. %.
3. One side is the egg test, the other side is the ovary or testis, this type is 40%.
Examine
True hermaphroditisal examination
Urinary 17-ketosteroids, estrogen and follicle stimulating hormone levels are generally within the normal range, karyotype 60% is 46, XX, 20% is 46, XY, and the rest are various types of chimeras, 46, XX /46,XY is more common.
B-ultrasound and urethra, vaginal angiography can be used to understand whether there is uterus, cryptorchidism and other deformities, laparoscopic help diagnosis.
Diagnosis
Diagnosis of true hermaphroditism
Diagnostic criteria
If the child is found to have abnormalities in the external genitalia after birth, he should immediately consult a specialist to make a diagnosis as soon as possible. He cannot simply make a simple diagnosis of simple hypospadias with cryptorchidism or scrotal division. The majority should be positive for chromatin examination. If the test does not conform to the normal male, for karyotype analysis, the karyotype analysis of the tissue cell chromosome is more helpful than the karyotype analysis of the blood cell. For the karyotype XX, the source of the female masculine phenotype should be carefully searched. Determination of various adrenal hormones, 17-ketosteroids, gestational triols, 17-dehydroprogesterone to exclude common types of congenital adrenal hyperplasia, histological examination found that both ovarian and testicular tissue can be clearly diagnosed, but sometimes due to gonads Improper development, making diagnosis difficult.
Differential diagnosis
1. Female pseudohermaphroditism: It is difficult to determine gender from the external genitalia, and the karyotype is 46XX, which is similar to the true hermaphroditism, but the 24-hour urinary 17-ketosteroid and gestational triol are increased. B-ultrasound, CT examination often shows double The lateral adrenal gland enlarges or has a place.
2. Male pseudohermaphroditism: It is difficult to determine gender from the external genitalia. It is similar to true amphoteric malformation, but 5-dihydrotestosterone is low. The gonadal biopsy has only testicular tissue and no ovarian tissue.
3. Klinefelter syndrome: It is difficult to determine gender from the external genitalia, similar to the true hermaphroditism, but the karyotype is 47XXY, and the gonadal biopsy has only testicular tissue and no ovarian tissue.
