Pediatric Androgen Insensitivity Syndrome

Introduction to androgen insensitivity syndrome in children Androgeninsensitivity syndrome (AIS) is a sexually linked genetic disease that is one of the causes of male pseudohermaphroditism, and occurs in people with a karyotype of 46, XY. The symptom of this symptom is that the patient's plasma androgen concentration is normal, but the target tissue lacks response or incomplete response to androgen, resulting in complete or partial loss of male characteristics of the patient, and the patient presents a female appearance. basic knowledge The proportion of sickness: 0.01%-0.05% Susceptible people: children Mode of infection: non-infectious complication:

Etiology of androgen insensitivity syndrome in children

(1) Causes of the disease

It has been confirmed that the disease belongs to a sexually linked type of hereditary disease, and it is believed that both the lack of androgen receptors and dysfunction are caused by genetic mutations, which may be alleles.

(two) pathogenesis

There are at least three mechanisms known to cause AIS to occur:

1. Androgen receptor deficiency or reduced number: Under normal circumstances, the action of androgen on the target organ to exert its effect depends on the sensitivity of the target cell, and this sensitivity is expressed by the interaction of androgen and its receptor. The androgen receptor can not only bind to dihydrotestosterone (DHT), but also bind to testosterone (T) in a non-covalent bond with high affinity. Testosterone and dihydrotestosterone are physiologically active in androgen. The strongest steroid hormone essential for the development of male accessory organs and their normal physiological functions. If the receptors are lacking or reduced in number, the effects of androgens will be affected. Most CAIS and a few PAIS are caused by males. Lack of hormone receptors.

2. Androgen receptor gene mutation causes dysfunction: Some patients have no significant changes in the number of androgen receptors, but there are defects in receptor function, mainly reflected in the binding of androgen to the receptor, which may be a genetic mutation. The resulting disorder of activation or transformation of androgen receptor complexes, many researchers have used specific monoclonal antibodies and CDNA probes to analyze the androgen receptor gene of patients to confirm the etiology of androgen insensitivity syndrome The basis is a genetic mutation in the androgen receptor.

3.5-reductase deficiency: The binding of androgen to target cells depends on two proteins, the androgen receptor and 5-reductase, and the 5-reductase converts testosterone into activity by binding to testosterone and its receptors. Stronger dihydrotestosterone, if the enzyme is lacking or the activity is weakened, affects the conversion of testosterone to dihydrotestosterone.

Prevention of androgen insensitivity syndrome in children

The disease belongs to a class of hereditary diseases, and the preventive measures should be from pre-pregnancy to prenatal:

Pre-marital medical examination plays an active role in preventing birth defects. The size of the effect depends on the examination items and contents, including serological examination (such as hepatitis B virus, treponema pallidum, HIV) and reproductive system examination (such as screening for cervical inflammation). General medical examinations (such as blood pressure, electrocardiogram) and asking about the family history of the disease, personal medical history, etc., do a good job in genetic disease counseling.

Pregnant women should avoid harmful factors as far as possible, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals, etc. In the process of antenatal care during pregnancy, systematic screening of birth defects is required, including Regular ultrasound examination, serological screening, etc., if necessary, a chromosome examination.

Once an abnormal result occurs, it is necessary to determine whether or not to terminate the pregnancy. The safety of the fetus in the uterus; whether there is sequelae after birth, whether it can be treated, how the prognosis, etc., take practical measures for diagnosis and treatment.

Complications of androgen insensitivity syndrome in children Complication

The position of the testis is variable, and it can be in the abdominal cavity or in the groin. After 25 years of age, there is more chance of testicular malignancy.

Symptoms of androgen insensitivity syndrome in children Common symptoms Labiac fusion amenorrhea

The clinical manifestations of androgen insensitivity syndrome are diverse, ranging between phenotypic women and almost normal men. The CAIS of phenotype is normal women is often found in primary amenorrhea, and a few are due to sputum surgery. The testis was accidentally found in the hernia sac or inguinal canal. The external genital tract was normal female, but the vagina was short and blind, there was no female genital tract, the female was in adolescence, the breast developed, but the pubic hair and the mane were absent. The PAIS phenotype is different in weight and weight, and may have a perineal clitoris, a hypospadias, a labia fusion, a large clitoris and a cryptorchidism. Or a normal male appearance, but only adolescent breast enlargement; can also be a non-reproductive male, the common phenomenon of various types of AIS is no Mullerian tube (the role of testicular-Muller tube inhibitor), and Wolff tube Dysplasia.

Examination of androgen insensitivity syndrome in children

The CAIS karyotype was 46, XY, and plasma testosterone, estradiol, and follicle-promoting concentrations were all at normal or normal high limits, while luteinizing hormone was elevated.

The fundus shows bilateral primary optic atrophy, hearing measurement shows mild neurological deafness, venous pyelography shows bilateral ureteropelvic ureteral dilatation, B-ultrasound visible vaginal short blind end, no cervix, no uterus and female reproductive tract, testis Abnormal position, etc.

Diagnosis and diagnosis of androgen insensitivity syndrome in children

1. According to the above clinical manifestations.

2. Chromosome examination, karyotype is normal male 46, XY.

3. LH and E2 increased in the body, but there was no significant change in T and FSH levels.

4. Diagnosis must rely on androgen determination and determination of androgen receptors in cells.

Different from female pseudohermaphroditism and true hermaphroditism, female pseudohermaphroditism patients have 46,XX karyotypes. The true hermaphroditism has dual genetic sex and dual sex gland sex, that is, both testicular and ovarian tissue.

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