[Grandmaternal age in children with Down syndrome in St. Petersburg].

Advanced maternal age is a well-established factor of DS occurrence. However the majority of DS cases are born to young couples. Some studies suggested that the risk for Down syndrome may be related to an aging grandmother. We obtained data on grandmaternal ages in 243 families of DS and 330 families of healthy children born in 1990-1999. The data were analyzed according to two categories of maternal ages, <30 yr and > or =30 yr. We did not find systematic differences in grandparental age distribution between the studied groups. Specifically, in 102 young couples with DS, medians for both maternal and paternal grandmother's age appeared to be equal (26 yr). Similar figures were observed in 284 young controls (27 yr). There was no difference in age distribution between 141 older couples with DS and 104 control couples. Therefore we failed to support the suggestion that advanced age of the DS grandmother is responsible for meiotic disturbance in her daughter. Neither the hypothesis suggesting a significant contribution of parentally transmitted trisomy 21 to DS population rate has been confirmed.

[Karyological characteristics of Down's syndrome: clinical and theoretical aspects]. / Kariologicheskaia kharkteristika bolezni Dauna: klinicheskie i teoreticheskie aspekty.

These data have been collected from St. Petersburg Down Syndrome Register that comprises information on 1778 liveborn children with the Down syndrome, including three twin sets, ascertained within 1970-1996. Karyotypes were obtained in 1223 cases, of which 1119 (90.7%) displayed regular trisomy. Mosaicism was found in 44 cases (3.6%), including 21 males and 24 females, and among these one familial case of mosaicism in a daughter and in a healthy mother. Of 70 cases of translocations, 41(5.7%) were Robertsonian D ones. 21 (17 inherited, 16 de novo and 8 of unknown origin), 28 translocations of isochromosomes 21q; 21q (1 inherited translocation 21; 22, 22 de novo and 5 of unknown origin). One child received the anomaly from his 46XX/45XX, t(D;G) mother-carrier. In 6 cases, free trisomy 21 was associated with structural or numerical anomalies: 46XY,t(13;14)mat + 21 in twins, 47XY,t(C;C) + 21, 47XY,t(10;15)pat + 21, 47XY,inv(19)mat + 21, 47XX + 21/48XX + 21 + ring, 48XXX + 21. In 12 families parental mosaicism was shown or suspected. In 6 families one parent had chromosome anomaly, in three cases it was not inherited: t(15;22) and t(6;21) in mothers and an additional small marker in a father. In cases confirmed cytogenetically an increased sex ratio was shown (679 males and 551 females, SR = 1.23), but it was not shown in patients not tested cytogenetically (264 males and 275 females, SR = 0.96, different from the expected 297 males and 242 females, P < 0.01).

[Mutational level of translocated variants of Down's syndrome in Leningrad (1982-1991)]. / Mutatsionnyi uroven' translokatsionnykh variantov sindroma Dauna v Leningrade (1982-1991).

Karyological study of 644 newborns with Down's syndrome (DS) revealed 37 translocation cases (5.7%). Translocations were inherited in 8 cases, in 17 cases they were sporadic, and in 12 cases parents were not examined. Total mutation rate per gamete per generation (2.7.10) and mutation rates of D/21 and G/21 translocations in different female age groups were calculated. The obtained data are in good agreement with results of research in other world regions. Literature data on the parental origin of de novo translocations for DS are presented. The role of meiotic coorientation of nonhomologous chromosomes in anomalies of spermatogenesis is discussed.

[Increase in the incidence and risk of birth of children with Down's syndrome in Leningrad (1982-1989)]. / Uvelichenie chastoty i riska rozhdeniia detei s bolezn'iu Dauna v Leningrade (1982-1989).

Among 559,286 infants born in Leningrad in 1982-1989, there was revealed 744 infants (1.33/1000) with Down's syndrome (DS). The age distribution for their mothers as well as for 79,571 parturient women in the general population was investigated. The data regarding the period studied was compared with the results of a similar investigation conducted during of 1945-1961. A decrease in maternal age in the population was demonstrated. This was more pronounced for the mothers of affected infants. A 1.4- to 2.2-fold increase of birth risks for DS was found in all maternal age groups. The doubling of the risk value occurred by the age of 30-34, in contrast to 35-39 in 1945-1961.

[Rare chromosomal aberrations in the Shereshevskii-Turner syndrome]. / Redkie khromosomnye aberratsii pri sindrome Shereshevskogo-Ternera.

Among 106 females with the Turner syndrome phenotype, two displayed rare chromosomal anomalies. In one patient, in addition to X-chromosome monosomy, among cultured lymphocytes cells with two isochromosomes made by long arms of X-chromosome were detected. Their frequency was 25%, and this value was the same in cultures obtained repeatedly after 3 and 5 months, which may suggest a certain stability of this clone. The other patient had a combination of two aberrations never reported before: the combination of isochromosome Xq and the Robertsonian translocation 13; 14. By their phenotype, these two women did not change from other patients with isochromosome Xq.

[Disorders in the lipid peroxidation system of the blood neutrophils of patients with the Shereshevskii-Turner syndrome]. / Narusheniia v sisteme perekisnogo okisleniia lipidov neitrofilov krovi u bol'nykh s sindromom Shereshevskogo-Ternera.

The neutrophil leukocyte test with the use of the antioxidant adrenaline was applied to study lipid peroxidation (LPO) in patients with Shereshevsky-Turner's syndrome. The data obtained point to the activation of LPO and reduction of the activity of the antioxidant system in neutrophil leukocytes.

[Dicentric Yp chromosome as one of the reasons for the absence of fluorescence in human Y chromosome]. / Ditsentricheskaia Yp-khromosoma kak odna ix prichin otsutstviia fluorestsentsii Y-khromosomy cheloveka.

In chromosome sets of three patients with Turner's syndrome non-fluorescent Y-chromosomes of normal size were found in part of the cells. C-, Q- and G-techniques have shown that they were dicentric Yp-chromosomes, resulting from a junction of long arms of two Y-chromosomes with simultaneous loss of the entire distal fluorescent segments. It is supposed that in some cases the non-fluorescent Y-chromosomes, previously described in literature, are as a matter of fact undiscernible dicentric Yp-chromosomes.

[Rare structural rearrangement of the Y chromosome (Yq-,S) in the family of a boy with a sex differentiation disorder]. / Redkaia strukturnaia perestroika Y-khromosomy (Yq-,S) v sem'e mal'chika s narusheniem polovoi differentsirovki.

In an 8-year old boy with bilateral cryptorchism the heterochromatin region deletion of Y-chromosome and the satellites in its long arm were found (karyotype 46, XYq-S). The same Y-chromosome was found in proband's father. Moreover, the proband had large brilliant satellites in the chromosome 22 and a very large segment of centromeric heterochromatin in the chromosome 1; both were inherited from his mother. The abnormal Y-chromosome is, probably, due to an exchange with heterochromatin regions between an acrocentric chromosome and Y-chromosome. The combination of above peculiarities of proband's chromosome set is supposed to promote the sex differentiation disorders in embryogenesis which led to an incomplete masculinization.

[Lipid peroxidation and the myeloperoxidase activity of neutrophilic leukocytes in shereshevskyi-Turner syndrome]. / Perekisnoe Okislenie lipidov i aktivnost' mieloperoksidazy neitrofil'nykh leikotsitov pri sindrome Shereshevskogo-Ternera.

The level of lipid peroxides, activity and thermostability of myeloperoxidase have been studied in neutrophil extracts from the peripheral blood of patients with the Shereshevsky-Turner syndrome and in normal subjects. A statistically significant rise in the level of lipid peroxides and respective decrease in the activity and thermostability of myeloperoxidase have been revealed in the patients as compared with the control group. These findings point to functional inferiority of neutrophils. It is probable that at the basis of the disorders seen there lie an abnormal set of sex chromosomes and upset hormonal regulation determined by the abnormality.

[Pericentric inversions of chromosomes 1, 9 and 16 in patients with sex chromosome anomalies]. / Peritsentricheskie inversii khromosom 1, 9, 16 u bol'nykh s anomaliiami polovykh khromosom.

Studies on C-heterochromatin in chromosomes 1, 9, 16 in 83 patients with the Shereshevsky-Turner syndrome and in 23 patients with the Klinefelter syndrome revealed the highest number of inversions in chromosome 9 and no inversions in chromosome 16. The inversion frequency in chromosomes 1 and 9 did not significantly differ from the control. Complete inversions were found only in the patients with isochromosome Xq, their frequency being increased in this group. A significant rise of complete inversions in chromosome 9 was found in a group of patients with Klinefelter syndrome. A tendency to inversion concentrations in chromosome 9 under human autosome anomalies, reported in the literature, was also detected in patients with sex chromosome anomalies.

[Platelet serotonin absorption in Turner's syndrome]. / Pogloshchenie serotonina trombotsitami u bol'nykh s sindromom Shereshevskogo-Ternera.

Functional activity of platelets was studied in 20 patients with Shereshevsky-Turner's syndrome. There was revealed a significant rise of platelet serotonin (5-hydroxytryptamine) content and also a reduction of exogenous serotonin absorption by platelets. The noted disturbances pointed to dysfunction of these cells, this serving as an auxiliary factor pointing out that the ageing process involved the blood elements. Reduction of platelet functional activity in patients with monosomia X was apparently due to chromosomic unbalance and with the associated hormonal control disturbances.

[Osmotic stability of erythrocytes in Turner's syndrome]. / Osmoticheskaia stoikost' eritrotsitov pri sindrome Shereshevskogo-Ternera.

Osmotic stability of erythrocytes was determined in 11 patients with Shereskevsky-Turner's syndrome and in 11 practically healthy persons. There was revealed an increased sensitivity of the patients' erythrocytes to the hypotonic NaCl solutions in comparison with the population of erythrocytes in control. Analysis of the age composition of the red blood cells demonstrated an increase in the number of young and old forms with an inadequate quantity of mature cells, this serving as a characteristic feature of the red blood in ageing. The results presented serve as an additional fact pointing to early ageing of patients with the Shereshevsky-Turner's syndrome.

[Human isodicentric X-chromosomes]. / Izoditsentricheskie X-khromosomy u cheloveka.

The large submetacentric abnormal late replicating X-chromosomes were found in three patients under karyological studies of 168 patients with Turner's syndrome. G- and C-banding revealed that abnormal chromosomes are three variants of isodicentric chromosomes resulting from the junction of the short arms of two X-chromosomes. The patients' karyotypes are respectively: 45,X/46,X,dic (X)(qter leads to p22: :p22 leads to qter); 46X,dic(X)(qter leads to p21: :p21 leads to qter); 46,X/46,X,dic(X)(qter leads to p11: :p11 leads to qter). All the three patients had different size deficiencies of the short arm of the X-chromosome. Partial X-monosomy caused the appearance of features of the Turner syndrome, which was less expressed in our patients compared to those with the entire X-monosomy.

[Familial X-autosomal translocation t (X, 2)]. / Semeinaia X-autosomnaia translokatsiia t (X, 2)

A loss of part of the short arm of the X-chromosome and a partial trisomy of chromosome 2 were detected in a girl with the Shereshevsky--Turner syndrome; her karyotype was 46, Xt (X,2) (Xqter leads to Xp11 : : 2q36 leads to 2q ter). The patient's mother had a balanced X-autosomal translocation 46, X,t, (X,2) (Xq ter leads to Xp11 : : 2q36 leads to 2q ter; 2p ter leads to 2q36 : : Xp11 leads to Xp ter). The daughter's abnormal X-chromosome was a late labelling one, while her mother had the late label in the normal X-chromosome.

[Identification of several chromosome aberrations in man by the fluorescent method using quinacrine yprite]. / Identifikatsiia nekotorykh khromosomnykh perestroek u cheloveka fluorestensentnym metodom s ispol'zovaniem akrikhi-iprita

The applications of the fluorescent staining of chromosomes with quinacrine mustard allowed to identify a dicentric Y-chromosome in two patients with defected external gynaetalies: a boy of 15 years old and a girl of 2 years old. Both the patients had mosaicism of sex chromosomes: 45, x/46, x dic (Y). The dicentric Y-chromosome, resembling chromosome, 16, had bright luminescence of the thelomeric regions characteristic of the normal Y-chromosome. Besides, a balanced autosomic translocation t (1, 14) (q 31, q 3) was found in the girl identified also with quinacrine mustard fluorescent staining.

[Study of the level of lipids in the blood serum of patients with Shereshevsky-Turner syndrome]. / Issleeovanie urovnia lipidov v syvorotke krovi bol'nykh s sindromom Shereshevskogo-Ternera

A comparative study of serum cholesterol, total lipoprotein and triglyceride level in patients with the XO karyotype and in normal subjects (XX) showed cholesterol and total lipoprotein to be increased in these patients; as to triglyceride level--it proved to be unchanged. The type of hyperlipoproteinemia was established in 7 of 18 patients examined; all of them under 30 years old. Thus, the incidence of hyperlipoproteinemia in the XO patients was sharply increased; this seems to be related to the low estrogen level.