scholarly journals Chromosome 21 non-disjunction and Down syndrome birth in an Indian cohort: analysis of incidence and aetiology from family linkage data

2010 ◽  
Vol 92 (3) ◽  
pp. 189-197 ◽  
Author(s):  
SUJOY GHOSH ◽  
PRANAMI BHAUMIK ◽  
PRIYANKA GHOSH ◽  
SUBRATA KUMAR DEY

SummaryWe analysed the family linkage data obtained from short tandem repeat (STR) genotyping of 212 unrelated Indian families having a single Down syndrome (DS) baby each, in order to explore the incidence and aetiology of this human aneuploidy in our cohort. The estimated values of maternal meiotic I and meiotic II non-disjunction (NDJ) errors of chromosome 21 (Ch 21) were ~78 and ~22%, respectively. Within the paternal outcome group, about 47 and 53% were accounted for NDJ at meiosis I and meiosis II, respectively. We estimated only ~2% post-zygotic mitotic errors. The comparison of average age of conception between controls and DS-bearing mothers revealed a significant difference (P<0·001) with DS-bearing women were on an average older than controls and meiotic II non-disjoined mothers were oldest among meiotic outcome groups. Our linkage analysis suggested an overall reduction in recombination by more than 50% on meiotic I non-disjoined maternal Ch 21 with error prone to susceptible chiasma formation within the ~5·1 kbp segment near the telomeric end. We stratified meiotic I non-disjoined women in three age groups, viz. young (⩽28 years), middle (29–34 years) and old (⩾35 years) and found linear decrease in the frequency of achiasmate meiosis from the young to the old group. In contrary, a linear increase in the multiple chiasma frequency from the young to the old group was observed. Considering these results together, we propose that the risk factors for Ch 21 NDJ are of two types, one being ‘maternal age-independent’ and the other being ‘maternal age-dependent’. Moreover, a comparison of our present Indian dataset with that of other published data of ethnically different populations suggested that the genetics that underlies the NDJ of Ch 21 is probably universal irrespective of racial difference across human populations. The present study is the first population-based report on any DS cohort from the Indian subcontinent and our work will help future workers in understanding better the aetiology of this birth defect.

Author(s):  
Tasuku Okui

This study aimed to identify differences in the trends of artificial and spontaneous fetal mortality rates between working and jobless households depending on ages, periods, and birth cohorts in Japan. Vital Statistics data from 1995 to 2019 and age groups in 5–year increments from 15 to 19 years through 45 to 49 years were used. Bayesian age–period–cohort analysis was used to evaluate changes in each of the outcomes. As a result, the difference in maternal age–standardized rate of both the artificial and spontaneous fetal mortality rates between the two types of households decreased in the periods analyzed. However, there was a statistically significant difference in the mortality rate between jobless and working households, regardless of maternal ages, periods, and cohorts for the artificial fetal mortality rate. A statistically significant difference was also observed for the spontaneous fetal mortality rates in some maternal ages, periods, and cohorts. In addition, the trend of birth cohort effects was particularly different between the two types of households for both the artificial and spontaneous fetal mortality rates.


2021 ◽  
pp. 1-9
Author(s):  
Sushil Kumar Jaiswal ◽  
Ashok Kumar ◽  
Amit Kumar Rai

Down Syndrome (DS) caused by trisomy 21 results in various congenital and developmental complications in children. It is crucial to cytogenetically diagnose the DS cases early for their proper health management and to reduce the risk of further DS childbirths in mothers. In this study, we performed a cytogenetic analysis of 436 suspected DS cases using karyotyping and fluorescent in situ hybridization. We detected free trisomies (95.3%), robertsonian translocations (2.4%), isochromosomes (0.6%), and mosaics (1.2%). We observed a slightly higher incidence of DS childbirth in younger mothers compared to mothers with advanced age. We compared the somatic aneuploidy in peripheral blood of mothers having DS children (MDS) and control mothers (CM) to identify biomarkers for predicting the risk for DS childbirths. No significant difference was observed. After induced demethylation in peripheral blood cells, we did not observe a significant difference in the frequency of aneuploidy between MDS and CM. In conclusion, free trisomy 21 is the most common type of chromosomal abnormality in DS. A small number of DS cases have translocations and mosaicism of chromosome 21. Additionally, somatic aneuploidy in the peripheral blood from the mother is not an effective marker to predict DS childbirths.


BMJ Open ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. e033334 ◽  
Author(s):  
Deborah A Marshall ◽  
Xiaoxiao Liu ◽  
Cheryl Barnabe ◽  
Karen Yee ◽  
Peter D Faris ◽  
...  

ObjectivesThe purpose of this study is to estimate the prevalence of comorbidities among people with osteoarthritis (OA) using administrative health data.DesignRetrospective cohort analysis.SettingAll residents in the province of Alberta, Canada registered with the Alberta Health Care Insurance Plan population registry.Participants497 362 people with OA as defined by ‘having at least one OA-related hospitalization, or at least two OA-related physician visits or two ambulatory care visits within two years’.Primary outcome measuresWe selected eight comorbidities based on literature review, clinical consultation and the availability of validated case definitions to estimate their frequencies at the time of diagnosis of OA. Sex-stratified age-standardised prevalence rates per 1000 population of eight clinically relevant comorbidities were calculated using direct standardisation with 95% CIs. We applied χ2 tests of independence with a Bonferroni correction to compare the percentage of comorbid conditions in each age group.Results54.6% (n=2 71 794) of people meeting the OA case definition had at least one of the eight selected comorbidities. Females had a significantly higher rate of comorbidities compared with males (standardised rates ratio=1.26, 95% CI 1.25 to 1.28). Depression, chronic obstructive pulmonary disease (COPD) and hypertension were the most prevalent in both females and males after age-standardisation, with 40% of all cases having any combination of these comorbidities. We observed a significant difference in the percentage of comorbidities among age groups, illustrated by the youngest age group (<45 years) having the highest percentage of cases with depression (24.6%), compared with a frequency of 16.1% in those >65 years.ConclusionsOur findings highlight the high frequency of comorbidity in people with OA, with depression having the highest age-standardised prevalence rate. Comorbidities differentially affect females, and vary by age. These factors should inform healthcare programme and delivery.


Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 248-253 ◽  
Author(s):  
Takao Komatsuda ◽  
Wenbin Li ◽  
Fumio Takaiwa ◽  
Seibi Oka

The vrs1 (formerly v) locus in the long arm of chromosome 2H controls lateral spikelet development in barley. The vrs1 locus was mapped by backcross-derived lines that consisted of 373 BC7F1 plants and 278 BC6F2 plants. The linkage study indicated that MWG801, CMNA-38/700, cMWG699, vrs1 and MWG865 exist in the order listed, with map distances of 3.1, 0.4, 0.1, and 0.9 centimorgans (cM), respectively. Recombination in female and male meiocytes showed no significant difference within this region. In a neighboring region between MWG865 and MWG503, the recombination frequency was higher in female than male meiocytes in one mapping population. The combined linkage data obtained from this study were compared with published data, and genotype-specific suppression of crossing-over was not evident in the vrs1 region.Key words: vrs1 locus (two- vs. six-rowed), molecular marker, recombination, backcross, Hordeum vulgare.


Twin Research ◽  
2001 ◽  
Vol 4 (1) ◽  
pp. 1-3
Author(s):  
Isaac Blickstein ◽  
Ran D. Goldman ◽  
Ram Mazkereth

AbstractIn order to examine birth weight characteristics of twins delivered to nulliparous mothers in relation to maternal age, we used a population-based cohort of Israeli twins delivered between 1993–98 to select all 4793 (37.6%) nulliparas who delivered twins. Maternal age was subdivided as less than 20 years, 20–24, 25–29, 30–34, 35–39, and 40 years or more. We counted the frequencies of each total twin birth weight (twin A+twin B) in each of three categories (less than 3000, 3000–4999, and more than 5000 g) and the frequency of very low birth weight (VLBW, less than 1500 g) neonates in each of the six maternal age categories. There were significantly more nulliparas in the twin population at age groups less 30 years and significantly less at ages 30 years or more. We found a highly significant inverse correlation between the proportion of nulliparas and maternal age group, decreasing from 71.8% at less than 20 years to 18.6% at age 35–39 years (% nulliparas = 85 − 13.7 × age group, Pearson R2 = 0.98). However, this trend changed abruptly to the observed figure of 25.9% nulliparas aged 40 years or more instead of the expected 2.8%. We failed to reveal any significant difference in birth weight characteristics between the maternal age groups (all p > 0.05, all confidence intervals included 1.0). The more than tenfold deviation of the observed from the predicted frequency of nulliparas aged 40 years or more suggests that a different relationship between parity and age occurs at this age group. Maternal age of nulliparas is not associated with different birth weight characteristics of their twins.


1977 ◽  
Vol 9 (4) ◽  
pp. 453-465 ◽  
Author(s):  
Susan Holloway ◽  
Alan E. H. Emery

SummaryThe incidence of Down syndrome in Scotland between 1960 and 1974 was estimated using data from thirteen Area Health Boards. Incidences in individual years, in different months of the year and in different maternal age groups were also determined. There was an apparent increase in incidence in more recent years almost certainly due to increased ascertainment. This may have obscured any decrease in incidence which might be expected as a result of a decrease in mean maternal age during this period and the introduction of antenatal diagnosis. No seasonal differences in incidence could be detected either in the whole area or in individual Area Health Boards. There was an increase in incidence with maternal age which was not significantly different from that found by other investigators. There was also an indication of an increase in relative incidence (% Down syndrome births/% live births) over the period 1966–74 in mothers aged 35 years and older.


2017 ◽  
Vol 4 (1) ◽  
pp. 27
Author(s):  
Riezqia Ayu Wulandari ◽  
Sandy Christiono ◽  
Niluh Ringga

Background: Down syndrome (DS) is a congenital disorder caused by abnormalities of chromosome 21, resulting in migration defect of neutrophils, specifically in GCF as a marker of increasing periodontal infection. This study aimed to analyze the difference in neutrophil numbers between down syndrome and healthy children.Method: This research was an analytic observational with cross sectional design, and divided into two groups. The control group is consisted of healthy children and the other is consisted of down syndrome children. GCF was taken using paper point number 45-50 for 30 seconds, then it smeared into object glass and painted with giemsa staining. Observations was done by light microscopy with 1000 times magnification.Result: The result of studies with p<0.05 was indicating a significant difference of neutrophil numbers between children with down syndrome and the healthy group.Conclusion: This study concluded that there was a difference in neutrophil numbers due to the migration defect of neutrophils in children with down syndrome, that can cause proneness to periodontal infections.


Author(s):  
Elham Masoumi ◽  
Zahra Malmir ◽  
Zahra Soleymani ◽  
Mina Mohammadi Nouri

Introduction: Expressive vocabulary plays a vital role in child language development, and its assessment can be one of the essential indicators to identify language developmental delay, especially in children with Down syndrome. We developed a list of expressive vocabulary and compared the size and class of expressive vocabularies between typically developing and Down syndrome children. Materials and Methods: Expressive vocabulary of 150 children was examined  in  this study. A total of 120 typically developing Farsi-speaking children (in four age Groups, with   a 6-month interval) and 30 children with Down syndrome (aged 24-48 months) participated in this study. The parents of the children filled out the form that included 636 words from different vocabulary classes. These classes were based on studies that investigated language development in Farsi-speaking children. Results: The expressive vocabulary size in Farsi-speaking children was significantly higher than in Down syndrome children (P≤0.001). There was no statistically significant difference between boys and girls regarding expressive vocabulary size in two Groups of children. The size of nouns in all age Groups is more than other classes, and the size of conjunctions in all age Groups is less than the other ones. A direct correlation was found between age and the size of expressive vocabulary. Conclusion: According to the study findings, the list of expressive vocabulary can detect delays in developing expressive vocabulary.


1970 ◽  
Vol 30 (3) ◽  
pp. 160-163
Author(s):  
P Goyal ◽  
R Singh ◽  
A Yadav ◽  
AK Dutta ◽  
J Bhattacharjee

Introduction: Down Syndrome (trisomy 21) provides an interesting natural model to study atherosclerosis, since these individuals appear to be protected from plaque formation. Methodology: We assessed the lipid levels, and superoxide dismutase (SOD) activity in 32 clinically diagnosed children of Down syndrome and 34 children matched for age and sex as controls. Results: SOD activity was found to be significantly higher (p=0.004) in children with Down Syndrome (mean=313.7 IU/ml) than in controls (mean140.2 IU/ ml). Significantly higher levels of serum triglyceride (154.7 mg/dl) and VLDL (33.9 mg/dl) were observed in Down Syndrome as compared to healthy controls (119.6 mg/dl and 23.9 mg/dl respectively; p<0.05 for each). However, the two groups did not show any significant difference in levels of serum HDL-C, LDL-C. Conclusion: The raised antioxidant activity of SOD, because of over expression of genes situated non chromosome 21, probably offers some protection against the development of atherosclerosis despite the occurrence of dyslipidemia. Key words: Chromosome 21; Down Syndrome; Trisomy 21; Superoxide dismutase.  DOI: 10.3126/jnps.v30i3.3919J Nep Paedtr Soc 2010;30(3):160-163


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