Congenital testicular hypoplasia syndrome (klinefelter syndrome)

Klinefelter of Massachusetts General Hospital and his colleagues first described this syndrome in 1942, so it was called Klinefelter syndrome. In 1956, Bradbury et al. found that X chromatin (Barr corpuscle) was positive in this kind of patients. In 1959, Jabobs and Strong confirmed that the patient's karyotype was 47, XXY (Figure 6-20). That is, there is one more X chromosome than normal men, also known as 47XXY syndrome.

The incidence of this disease in male newborns is 0. 13%. That is, there are l patients among 850 people, accounting for 1/20 of male infertility. The main clinical features of the patient are: the patient is male in appearance, asymptomatic in childhood, and the symptoms become more and more serious after puberty. The patient is slim and weak. Male genitalia, short penis, small testicles or cryptorchidism. Testicular tissue section showed that renal tubules were glassy and could not produce sperm, so they were infertile. About 25% of patients can develop into female breasts by puberty. Axillary hair and pubic hair are rare or absent; The beard is sparse, the Adam's apple is not obvious, the subcutaneous fat is developed, the skin is delicate like a woman, and the temperament and posture tend to be feminine. Some patients have mental retardation, but most of them have normal intelligence. Some patients are mentally abnormal or prone to schizophrenia. Patients' mothers are usually older. The karyotype of 80% ~ 90% patients is 47, XXY；; About 10% ~ 15% is chimeric, and the common karyotypes are 46, XY/47, XXY；; 46, XY/48, XXXY, etc. If the proportion of 46, XY normal cells in chimera patients is large and the clinical manifestations are light, they can have fertility. And 48, XXXY；; 49, XXXXY, etc. Due to the function of redundant X chromosomes, the more X chromosomes, the more serious the symptoms.

2. The best brandy (special grade)

Congenital ovarian hypoplasia syndrome (Turner syndrome)

In 1938, Turner reported 7 cases of short stature, immature sexual development, webbed neck and cubitus valgus. 1954 Polani et al. found that many cases of Turner syndrome have X chromatin negative and ovarian hypoplasia. It was not until 1959 that Ford discovered that the patient's karyotype was 45, x, which was the earliest sex chromosome abnormality found. So Turner syndrome is also called 45, X or 45, XO syndrome.

The incidence of Turner syndrome in newborn girls is 1/250 o- 1/5000. In spontaneous abortion embryos, the incidence can be as high as 7.5%. According to the data, it is speculated that 98% of 45, X embryos will have spontaneous abortion, and only about 2% of those with mild dysplasia can survive.

The patient's appearance is female, with short stature (120 ~ 140 cm) and low hairline. About 50% patients have webbed neck, stiff face, cubitus valgus, shield chest, wide breast spacing, undeveloped breasts until puberty, nipple dysplasia, cord gonad, external genitalia of infants and primary amenorrhea. Some patients have mental retardation. Karyotype analysis showed that the patient's karyotype was 45, and X, X chromatin and Y chromatin were all negative (Figure 6-2 1). About 15% of them are chimeras with karyotypes of 45, X/46 and XX. When the proportion of abnormal karyotype is small, the clinical signs are atypical, such as short stature, primary amenorrhea, cord gland and so on. Some patients may have menstruation. If 46, XX cells are dominant, the phenotype looks like normal individuals, and they can get pregnant, but their fertility is reduced.

3.XXX，XXXX，XXXXX

Trisomy x syndrome and multiple x syndrome

1959, Jacobs and others first described a woman with three X chromosomes, and called it a superwoman. This is a common chromosomal abnormality in women. The incidence of newborn girls is about11000. It accounts for about 4/ 1000 of female mental patients. There is no obvious abnormality in trisomy X women, and about 70% cases have normal development of secondary sexual characteristics in adolescence and can give birth. About 30% patients have irregular menstruation, primary or secondary amenorrhea or premature menopause, breast dysplasia and abnormal ovarian function, and about 2/3 patients have slightly lower intelligence and are prone to mental illness. Except 47, XXX, some patients have chimera karyotype, and the symptoms are generally mild. Theoretically, half of the offspring of 47, XXX females should have 47, XXX or 47, XXY karyotypes. But in fact, more than 30 children born to women above 10 47 and XXX have normal karyotypes. The explanation for this phenomenon is that in the first meiosis of women, the nucleus with XX almost always enters the polar body and is eliminated. There are also patients with 4 or even 5 X chromosomes. Generally speaking, the more X chromosomes, the more serious the mental damage and developmental deformity. Some data show that the mothers of patients with this disease are older than the control group. Almost all the extra X chromosomes come from the non-segregation of maternal meiosis, and mainly in the first time.

4.XYY，XYYY，XYYYY

XYY syndrome

196 1 was first reported by Sandberg and others, also known as super male. 1965, Jacob et al. examined the chromosomes of 197 male prisoners with violent behavior tendency, and found that 7 cases were such patients, and proposed that the existence of two Y chromosomes might be related to infringement, thus attracting people's attention.

The incidence of male is about1/750 ~1500. The incidence of males in prisons and mental hospitals is relatively high, accounting for about 3%. The main clinical manifestations of the disease are mostly men with normal phenotype, tall and often exceeding 180cm, and the incidence frequency tends to increase with the increase of personal height. Most of them have fertility, and occasionally hypospadias, cryptorchidism, testicular hypoplasia, spermatogenesis process disorder and fertility decline. These patients have normal intelligence, but they are grumpy, rude and aggressive, and often commit aggressive crimes. At this time, the EEG showed abnormality, and the age of crime was relatively young, with an average of 13.438+0 years.

In addition to the 47, XYY karyotype, there are 48, XYYY；; 49, XYYYY type patients, but rare. These patients are impatient and have poor mental development, finger deformities.

5. only y

Does not exist. The y chromosome is much smaller than the x chromosome. X chromosome contains a large number of genes that Y chromosome does not have. So it's impossible not to have an X chromosome.