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At least 19 recordsLinked to original sources
PubMed1977

[Chromosome 8 : complete trisomy and segmental trisomies].

The phenotypic effects of trisomy of various segments of chromosome 8 have been recognized through the analysis of twelve different patients: five mosaic cases of trisomy 8, one case of trisomy for the short arm and the proximal segment of the long arm, two cases of trisomy for a portion of the short arm, and four cases of trisomy for the terminal segment of the long arm. Analysis of the data from the literature and of these personal observations allows the definition of three syndromes: trisomy 8, trisomy 8p and 8q proximal, and trisomy 8q terminal. Three clinical signs are common to the three syndromes: vertebral anomalies, depression of the mesosternum, and bulging of the forehead. This suggests that different segments of chromosome 8 carry genes affecting osseous growth. Trisomy 8p causes, in addition to severe mental deficiency, a thick nose, a large mouth, and microcephaly. Other clinical signs can be assigned to three groups corresponding to the short arm, the proximal part, and the distal part of the long arm.

Abnormalities, Multiple↗
PubMed1978

The ratio of de novo unbalanced translocation to 47, trisomy 21 Down syndrome. A new method for human mutation surveillance and an apparent recent change in mutation rate resulting in human interchange trisomies in one jurisdiction.

The Down syndrome phenotype may be associated with, among other genotypes, an unbalanced Robertsonian translocation producing an "interchange trisomy" with 46 chromosomes, or 47, trisomy 21. Translocations, like specificlocus point mutations, result from a direct change in structural chromosome elements. In contrast 47, trisomy 21 results from meiotic non-disjunction. Mutation rates for interchange trisomies may be followed indirectly by determining the ratio of instances of Down syndrome associated with a new translocation mutation to those produced by 47, trisomy 21, which accounts for the bulk of the Down syndrome phenotype. This genotypic ratio can be analyzed in data from cytogenetic laboratories, clinics, and chromosome registries and does not depend upon intensive chromosome screening of newborn populations. A similar approach can be adopted to follow trends in Patau syndrome. The genotypic ratio, stratified by maternal age, may in addition, provide a sentinel index for changes in human specific-locus mutations and perhaps other adverse health consequences. Analysis of data from the New York State-North-eastern chromosome registry revealed a two- to three-fold increase in the genotypic ratio for both Down syndrome and Patau syndrome for individuals born in 1973, 1974 and 1975 compared to those born in earlier years.

Down Syndrome↗
PubMed1977

Regular G21-trisomy in 3 sibs from mother with trisomy 21 mosaicism.

This paper describes a family with 3 affected sibs with regular trisomy 21 Down syndrome. The condition seems to be transmitted from a phenotypically normal mother in whom G-trisomy mosaicism was identified. Giemsa banding depicted trisomy 21 mosaicism in cells from the mother. Chromosomes from the children showed a trisomy 21 in all the cells analysed.

Adolescent↗
PubMed1977

Partial trisomy 21. Further evidence that trisomy of band 21q22 is essential for Down's phenotype.

Cytogenetic analysis of a 6-year-old girl with moderate mental retardation revealed 46 chromosomes with a tandem translocation (21;21) resulting in a partial trisomy 21. Only the terminal band 21q22 was not in triplicate. G-, Q-, R-, and C-banding techniques and silver nitrate staining of the nucleolus organizer regions (NORs) were used to identify this chromosome fully. The phenotype of the patient was not typical for Down's syndrome, providing additional evidence that trisomy of band 21q22 is pathogenetic for the phenotype of Down's syndrome. This is also a new example in human pathology of a stable 'dicentric' chromosome in which one of the centromeric constrictions appears to be nonfunctional.

Centromere↗
PubMed1978

Double trisomy as a mosaic. Case history (48, XYY, + 21/47,XY, +21) and survey of the literature of mixed autosomal-gonosomal trisomies.

The case of a boy is reported showing the typical symptoms of Down's syndrome, in whom the chromosome analysis revealed a mosaic karyotype: 50% 48,XYY,+21/50% 47,XY,+21. Findings of 92 cases from the literature are summarized to show the frequencies of double gonosome-autosome aneuploidies compared with single trisomies. Referring to the different chromosomes involved, the aneuploid cell formation, the frequencies of combinations, as well as the tendency to mosaic formation are analyzed. The age of parents at the time of birth and the life expectancy are described as well as the clinical symptoms. Theories concerning the origin of double aneuploidies are discussed.

Aneuploidy↗
PubMed1976

[Genetic studies in patients with trisomy 21 with special evaluation of morphology and pathogenesis in the orofacial region. Condition of periodontal and oral hygiene in trisomy 21].

The incidence and severity of parodontopathies and results of studies of the level of oral hygiene are reported, in terms of both subjective and objective parameters, for children and juveniles affected with trisomy 21. Also discussed are problems of age and sex dependence; causal, complementary, and reciprocal relationships; and possibilities of prophylaxis.

Adolescent↗
PubMed2025

Analysis of prenatal diagnosis and pregnancy outcomes for rare autosomal trisomies detected by non-invasive prenatal testing in 33,079 cases.

BACKGROUND: Non-invasive prenatal testing is widely used for screening common fetal aneuploidy disorders such as trisomy 21, trisomy 18, and trisomy 13. However, its ability to detect rare autosomal trisomies has introduced a new layer of complexity and clinical uncertainty. METHODS: A retrospective analysis was conducted on the prenatal diagnostic results and pregnancy outcomes of cases identified as high-risk for rare autosomal trisomies through non-invasive prenatal testing at the reproductive medicine center, Renmin hospital, Hubei university of medicine, from 2015 to 2023. RESULTS: 66 cases identified as high-risk for rare autosomeal trisomies, yielding a detection rate of 0.20% (66/33,079). 7 declined amniocentesis, while the others underwent the procedure. Prenatal diagnostic procedures did not confirm the presence of the corresponding rare autosomal trisomy in any of these cases. Among the 66 cases of rare autosomal trisomies (RATs), 5 cases were lost to follow-up, and 1 case underwent termination of pregnancy (TOP) for personal reasons, leaving 60 cases with valid pregnancy outcomes. Of these 60 valid outcomes, 50 (83.33%) resulted in full-term births, while 10 (16.67%) experienced adverse pregnancy outcomes. CONCLUSION: Prenatal diagnosis for high-risk rare autosomal trisomies typically reveals a normal karyotype with no detectable chromosomal abnormalities, and most cases can achieve full-term pregnancy outcomes. However, adverse pregnancy outcomes such as preterm birth, fetal demise, placental abnormalities, and intrauterine growth restriction are common and should be given clinical attention and consideration.

Humans↗
PubMed1979

[Neonatal thrombocyte values in children with Down's syndrome and other autosome trisomies].

Platelet counts were determined in 70 neonates with trisomy-21, 10 neonates with trisomy-18 and 6 neonates with trisomy-13 during the first days of life. 60% of all infants with trisomy-aberrations were found to have thrombocytopenia. Platelet counts in Down's syndrome averaged 104600 (SD 53000; median 90500; 10- and 90-percentile at 45000 and 175000) per microliter. A correlation with other hematological features of trisomy-21 was examined. There was no significant correlation between platelet counts and hemoglobin concentration. Similarly the difference in platelet counts between trisomy-neonates with and without polycythemia was statistically not significant. In contrast, 27 normal neonates with polycythemia showed significantly higher platelet counts (mean = 13400) than their trisomy-counterparts (mean = 98900; P = 0.01). In addition, there was no correlation, in trisomy infants, between either erythroblastosis or low birth weight and platelet count. These findings point to defective hematopoiesis as a primary cause of thrombocytopenia in trisomy-infants.

Birth Weight↗
PubMed1976

Familial 'partial 9p' trisomy: six cases and four carriers in three generations.

Six cases of translocation trisomy for the distal half of the short arm of a number 9 chromosome and four asymptomatic balanced translocation carriers are presented in a three-generation pedigree. The clinical features are remarkably similar to those recently recognized and increasingly reported in full short arm (9p) trisomy and should be considered a modification of the same syndrome. In addition to non-specific mental retardation and short stature, there is, in common, a characteristic facies, including down-turned corners of the mouth, a slightly bulbous nose, moderately large ears, suggestively wide-set eyes with an antimongoloid slant, dysplasia and hypolasis of the nails, clindactyly of the 5th fingers, and abnormal dermatoglyphs. It appears that the 'trisomy 9p syndrome' in its variant forms, including trisomies for more or less than just the short (p) arm, is one of the most common clinical autosome anomalies in humans, exceeded only by trisomy 21 (Down's syndrome) and possibly trisomies of chromosomes 13 and 18.

Adult↗
PubMed1979

Partial trisomy 1 due to 1/17 translocation in Ph'-positive chronic myelocytic leukemia.

A patient with chronic myelocytic leukaemia (CML) had the Philadelphia chromosome from the standard 9/22 translocation, a partial trisomy 1 secondary to an unbalanced 1/17 translocation, and a more recent clone with the addition of trisomy 22. This is the third case of partial trisomy 1 associated with the Philadelphia chromosome. Trisomy 1 in haematological disorders is discussed with reference to its clinical significance in CML, the segment of chromosome no. 1 involved, and the mechanism of origin of the partial trisomies. Anomalies of chromosome 1, although not specific to any of them, seem to be important in the development of myeloproliferative disorders and of neoplasms in general.

Chromosomes, Human, 1-3↗
PubMed1977

Double autosomal trisomy: case report (48, XX, +18, +21) and review of the literature.

A twelve-months-old female is reported with double trisomy of the autosomes 18 and 21 (48,XX,+18,+21), exhibiting the clinical features of mongolism. The findings of this patient and the data of fourteen previously reported cases with double autosomal trisomy, twelve of them mosaics, may be summarised as follows: The mean birth weight was lower than in the single trisomies D, E, and G. The distribution of the maternal ages at birth of the patients was striking: six mothers were younger than 21 years, seven mothers were older than 34 years. In those patients with prevalence of one of the two extra chromosomes in their karyotypes, the corresponding trisomy syndrome also predominated clinically. In those cases with an equal proportion of both additional chromosomes there were as many patients with clinical predominance of the one as of the other trisomy syndrome. Survival beyond the second half of the first year of life was seen only in those patients who showed the clinical picture of mongolism.

Birth Weight↗