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Biomedical subjects

I V Butomo

Publications and source records attributed to I V Butomo.

At least 19 recordsLinked to original sources
PubMed2002

[Results of estimation of mutation rates for translocation trisomy 21].

Among 1332 cases of trisomy 21 born within 1979-1999 in St. Petersburg, 76(5.7%) were carriers of a translocation between chromosome 21 and other acrocentrics. Among 43 Dq; 21q translocations, 17 were inherited from the mother, and one was inherited from the father, 16 were of sporadic occurrence, and in 9 cases the mode of inheritance was not established. Out of 31 cases displaying Gq;21 translocation, 23 were mutants and 8 of unknown origin. One case of non-Robertsonian translocation 21;22 was maternal in origin. It was assumed that the proportion of sporadic cases among translocations of unknown origin is the same as that among translocations of the known origin. However, it is conceivable that the parents of a child with a sporadic anomaly, previously having an uncomplicated reproductive history and healthy children, tend to avoid cytogenetic examination more often than the carriers of translocation. Hence, the reported proportion of de novo cases (-0.6) might be underestimated. The analysis of pregnancy outcomes in mothers of children with Down syndrome, who inherited translocation (n = 12), sporadic translocation (n = 12) and translocation of unknown origin (n = 8), supports this suggestion. Analysis of the data from 8 reports, where the origin of Dq;21 was specified, revealed that in those samples, where the origin was traced in almost all families, the proportion of de novo cases (0.75-0.82) was higher than in samples where an appreciable part of families was not examined (0.46-0.73). Therefore, with the aim of correct determination of mutation rate for Dq;21 translocation, the true proportions in D;21 cases merit evaluation. Meanwhile, using average estimation from all the above mentioned reports (0.67), the mutation rate for translocations Dq;21 in St. Petersburg was calculated to be 1.2 x 10(-5) and 0.8 x 10(-5) in 1980-1989 and 1990-1999, respectively. For Gq;21 translocations/isochromosomes, the corresponding figures were 1.6 x 10(-5) and 1.5 x 10(-5).

Adult↗
PubMed1999

[Karyological characteristics of Down's syndrome: clinical and theoretical aspects].

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).

Chromosome Aberrations↗
PubMed1994

[Increase in the incidence and risk of birth of children with Down's syndrome in Leningrad (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.

Adult↗
PubMed1994

[Mutational level of translocated variants of Down's syndrome in Leningrad (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.

Chromosomes, Human, Pair 14↗
PubMed1993

[Acrocentric chromosomal associations in the families of children with Down's disease].

Acrocentric chromosome associations were studied in 373 persons: children with Down's syndrome, their parents and in controls. In parents with nondisjunction in the first meiotic division (M1) and in children with trisomy 21 due to parental nondisjunction in the M1 the increase of association activity of chromosome 21 was found out, compared with the parents-donors of the extrachromosome due to meiotic 2 (M2) errors, their children and control. The increased frequency of chromosome 21 associations in the whole group of parents (without taking into consideration the origin of odd chromosome) is also observed. It is particularly stressed that under studying the extrachromosome origin by cytological method the accumulation of marker variants of chromosome 21 occurs in groups of donors of the extrachromosome and their partners. This causes the absence of differences in association frequency between donors and donors' partners and prevents to study the integral picture of various factors contribution in the etiology of nondisjunction.

Adult↗
PubMed1993

[Polymorphism of C-heterochromatin chromosome regions in the etiology of human aneuploidy].

Cytogenetic study of the C-heterochromatic polymorphisms in 202 individuals from the Down's syndrome families and in 31 control individuals was undertaken. In 58 families the source of an additional chromosome was taken into account. It was shown that in the donors of extra chromosome, due to nondisjunction in the Ist meiotic division, the frequency of heteromorphism was higher (0.61) than in other groups: donors with the 2nd meiotic nondisjunction (0.44), partners of donors (0.48) and controls (0.46). Also, increase in heteromorphism rate was found in a group of young mothers (0.56) compared with a group of old mothers (0.45). The role of heterochromatic regions in chromosome nondisjunction is discussed from the point of view of meiotic nonhomologues coordination.

Adult↗
PubMed1988

[The origin of an extra chromosome 21 in families of children with Down syndrome].

These are the first studies on the origin of nondisjunction of trisomy 21 in the USSR. Parental contribution was established in 84 of 140 families observed. In 66% cases the nondisjunction took place in oogenesis and in 34% cases - in spermatogenesis. Among the children, who inherited the additional chromosome from father, boys predominate. Compilative work on all the data available concerning the origin of the 21 nondisjunction has been performed; the factors favouring nondisjunction in I and II mitotic divisions in female meiosis, both genetical and age-dependent, have been considered. The great importance of the disturbances taking place in spermatogenesis for etiology is emphasized. It is proved that somatic hyperploidy does not serve as an indicator of predisposition for chromosome nondisjunction in meiosis.

Adult↗
PubMed1981

[Prenatal diagnosis of the cri-du-chat syndrome in the case of balanced 5p--; 18p+ translocation in the mother].

The case studied is taken to emphasize the high risk of anomalous progeny being delivered from couples, who are the balanced translocation carriers. The "cri du chat" syndrome was diagnosed in a woman carrier of the balanced reciprocal translocation t(5, 18) (5p13; 18p11) during two successive pregnancies: the diagnosis was postnatal in the first pregnancy, and prenatal in the second. The prenatal diagnosis of the 5p--syndrome was made in amniotic fluid cell culture and verified in fetal skin culture obtained through fetal biopsy. A wider network of prenatal diagnosis services, primarily for couples carrying balanced chromosome rearrangements, could greatly contribute to the task of preventing severe hereditary diseases.

Abortion, Induced↗
PubMed1977

[Possible disorder of tissue immunity function in mothers who have given birth to a child with Down's disease].

The rates of DNA synthesis were studied in PHA-stimulated lymphocytes from the peripheral blood of mothers giving birth to a child with Down's disease. For control purposes a group of donors of the same age and sex were studied as wells. A decrease of 3H-thymidine incorporation was detected in the lymphocytes of the mothers of such children. The found differences were due to a drop of lymphocyte PH-reactivity in the older maternal age group (over 30 years). Interrelation between the changed function of the maternal immune system and the birth of children with chromosome unbalance are discussed.

Adult↗
PubMed1977

[Double autosomal aberration: trisomy 21 and familial reciprocal translocation t(10;12)(p14;q21)].

A child with the Down syndrome revealed besides a regular trisomy 21, an enlargment of the short arm of chromosome 10, and the deletion of the long arm of chromosome 12. The proband's mother, who was phenothypically normal woman, appeared to be a carrier of the reciprocal translocation, her karyotype being: 46, XX, rep (10;12) (10qter leads to leads to 10p14; 12q21 leads to 12qter; 12pter leads to 12q21 : 10p14 leads to 10pter). Hence, the proband had double chromosomal aberration 47, XX, +21, rcp (10; 12) (10qter leads to 10p14 : 12q21 leads to leads to 12qter; 12pter leads to 12q21 : 10p14 leads to 10pter) mat. There is no reason to relate hard manifistation of the Down syndrome with the detected translocation. The influence of the mathernal non-devision in the meiosis and the rise of the trisomy 21 is discussed. In the following pregnancies it is advisable to amniocentesis.

Adult↗