Klinefelter syndrome (dysgenesis of the seminiferous tubules) –
sex chromosomal abnormality disease
A terrible symptom of which is a violation of spermatogenesis.
The frequency of the disease among persons with a male phenotype is
1: 1100, among men who suffer from bleeding, 1: 9, and among
oligophrenics – 1:95.
Historical data. For the first time the syndrome is described by Kleinfelter.
in 1942
Etiology. The cause of the disease is unknown.
Pathogenesis. The disease is caused by a chromosomal abnormality.
Patients most often have one extra X chromosome, less often –
several X chromosomes (karyotype 47XXY; 48XXXY; 49XXXXY).
In some cases, the Y-chromosome polysomy is detected during mono-
somi on the X chromosome, as well as polysomy on the X and Y chromosome
(G. G. M and r za ya n c). Patients with mosaicism sex chromosomes
may be different in different tissues. In connection with this ill
can be detected with negative sex chromat
not. Mosaicism is most often represented by 46XY / 47XXY. In embrio
national period formation of testicles and male genital organs
occurs normally due to the presence in the karyotype
Y chromosomes. However, in puberty, there are
irregular changes of the testicle in violation of its normal times
development and function. Insufficient testosterone secretion
leads to a sharp increase in gonadotropic hormones,
formation of eunuchoid body proportions, poor development
secondary sexual characteristics, etc.
Pathological anatomy. Histologically with testicular biopsy
in the postpubertal period, there is no spermatogenesis, sclerosing hyalinization of its own membrane
small tubules. There is a marked degeneration of the sustentocytes.
and hyperplasia of testicular glandulocytes. Histological structure
testicular until puberty normal.
Clinic. Patients complain of underdevelopment
genitals, breast enlargement, lack of growth
facial hair, infertility, etc. The disease manifests itself
during puberty. In the classic form of Kline syndrome
felter patients tall, the proportions of the body eunuchoid:
disproportionately extended compared to the body of the end
women, fat deposition by female type, wide pelvis, narrow
shoulders, characterized by true gynecomastia (Fig. 69).
Secondary sexual characteristics are mild: poor ovo
elk on the face, in the armpit, on the pubis – for women
sky type. The penis is usually of normal size. Testicles
often small, flabby, sometimes dense. Libido is often preserved, but due to azoospermia, patients are infertile.
Intellect is often reduced. It has been established that mental retardation
increases with the number of X chromosomes. When the karyotype
49 XXXY usually happens I am mental retardation, often
cryptochism.
Sometimes there are changes in the organ of vision: bilateral
epicanthus, point opacities of the lens capsule, coloboma
iris and choroid proper.
Laboratnoi d. Marked azoospermia.
Blood levels of gonadotropic hormones, hormone
growth, reduced testosterone levels. Glucose tolerance is not
rarely lowered until the development of diabetes.
Testosterone excretion with urine is reduced, and urinary excretion
estrogen may be elevated. Insignificant
decrease in urinary excretion of total 17-CU and their individual coat
tions (androsterone, etiocholanolone).
D ia and gnostas and with to and e pp ob. In order to determine
genetics conduct research on sex chromatin and
chromosomal complex. Sex chromatin with this syndrome
usually positive. In the study of the chromosomal complex
the karyotype 47XXY is most often detected (Fig. 70). When ill
polysome on the Y chromosome, the karyotype can
be 47XYY, 48XYYY with negative sex chromatin.
In the case of mosaicism, sex chromatin may be a negative
nym or positive.
R e nt g en d d а а gn o s t i k а. When craniography Turkish
saddle of usual form and size. Often there are hyperpneuma
tization of the sinus of the main bone, delayed maturation of the bones
skeleton without disrupting bone structure.
Diagnosis and differential diagnosis. Before puberty
to diagnose Klinefelter’s syndrome
tel. When diagnosing during puberty, they turn on
attention gynecomastia, the development of male wto
sexual signs, azoospermia. Crucial at
diagnosis have sex chro data
matin and chromosomal complex.
Klinefel syndrometera is differentiated from other forms of hypogonadism. In contrast to Klinefelter’s syndrome, when acquired hypogonadism, the karyotype 46XY, the absence of sex chromatin, are noted. In some cases, gynecomastia with Klinefelter’s syndrome is differentiated from pubertal gynecomastia. With the latter, in contrast to gynecomastia, Klinefelter syndrome shows normal physical and sexual development, the 46XY karyotype, and the absence of sex chromatin. Forecast. With regular long-term replacement therapy, muscle strength increases, overall health improves. However, with regard to full recovery, the prognosis is poor. Patients remain barren. Vegetation on the 407 face usually does not increase. The ability to work depends on the degree of mental retardation. Treatment. Substitution therapy is carried out with preparations of male sex hormones or their synthetic analogues (see “Primary hypogonadism”). Replacement therapy is usually ineffective due to a decrease in the body’s sensitivity to androgens.