The maternal age-specific live birth prevalence of trisomies 13 and 18 compared to trisomy 21 (Down syndrome)

ABSTRACTThis study aims to investigate the trends in maternal age distribution and estimate the live birth and population prevalence of Down’s syndrome in China.Using population survey data, we demonstrated the change of maternal age over the past three decades and its effect on the live birth prevalence of Down’s syndrome. We also integrated the live birth prevalence and the survival rate to estimate the population prevalence of Down’s syndrome. Chi-square test was used to compare the maternal age distributions across survey years.The results show that the maternal age has been rising over the past 30 years in China at national level. The proportion of mothers aged 35 and over increased from 3.62% in 1985 to 14.40% in 2010. The estimated live birth prevalence of Down’s syndrome has mirrored the same increase of the maternal age from 1.07 per 1000 live births in 1985 to 2.36 per 1000 live births in 2010. At City level, the change of maternal age and live birth prevalence of Down’s syndrome were more significant than at Town and County levels. The proportion of mothers aged 35 and over increased from 2.17% in 1995 to about 16% in 2010 at City level, while it increased from 2.03% to 13.65% at County level. The total estimated number of people with Down’s syndrome who were still alive in 2012 and aged below 27 was 611,053, and the estimated population prevalence is 0.45 per 1000.To conclude, this study provides a clear message about the rising trend in maternal age in both urban and rural areas in China since 1985 and its effect on the estimated birth prevalence with Down’s syndrome. The regional differences should be taken into account for planning population policy and allocating medical resources to reduce the burden of family with Down’s syndrome.

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Down Syndrome Survey in South Indian Population- Understanding Inheritance, Perceptions, Interventions and Diagnosis

International Journal of Human Genetics ◽

10.31901/24566330.2021/21.04.792 ◽

2021 ◽

Vol 21 (04) ◽

Author(s):

Disha Sawhney

Keyword(s):

Down Syndrome ◽

Genetic Counseling ◽

Trisomy 21 ◽

Maternal Age ◽

Indian Population ◽

Advanced Maternal Age ◽

South Indian Population ◽

Adhd Symptoms ◽

Hyperactivity Disorder ◽

South Indian

ABSTRACT Down syndrome (DS) has been prevalent worldwide, for centuries now. Despite the fact that tremendous research has been done on DS ever since the early 1950s, most results obtained, are on the basis of etiological and demographic factors and predominantly of the western data. Every year in India, >30,000 children are born with DS. This survey has been done keeping the Indian population in mind and to analyze the outlook of parents having children with DS, understand the comorbidities and their management. The study was conceptualized to create an exhaustive and comprehensive questionnaire to study the pattern of inheritance of Trisomy 21, analyze influence and correlation of advanced maternal age, sex ratio, order of birth, hypothyroidism, common comorbidities, abortions, Attention deficit hyperactivity disorder (ADHD) and sleeping difficulties in individuals diagnosed with DS. 50 family triads were interviewed. The results showed that incidence of DS was more in males compared to females. The analysis revealed that mean maternal age of 25-28 years showed increased incidence of DS. 2.5 percent showed severe ID and 27.5 percent had severe ADHD symptoms, while 10-13 percent showed mild to moderate ADHD. The most and least prevalent comorbidity seen was the presence of heart disease (45%) and hearing impairment (10 percent) respectively. It was found that about 40 percent of parents strongly agreed to the idea that Genetic Counseling (GC) is helpful and wanted to reinforce it to others who find it difficult to cope up with their DS child.

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Estimates of live birth prevalence of children with Down syndrome in the period 1991-2015 in the Netherlands

Journal of Intellectual Disability Research ◽

10.1111/jir.12371 ◽

2017 ◽

Vol 61 (5) ◽

pp. 461-470 ◽

Cited By ~ 14

Author(s):

G. de Graaf ◽

J. J. M. Engelen ◽

A. C. J. Gijsbers ◽

R. Hochstenbach ◽

M. J. V. Hoffer ◽

...

Keyword(s):

Down Syndrome ◽

The Netherlands ◽

Live Birth ◽

Birth Prevalence ◽

Children With Down Syndrome

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A terhességet megelőzően alkalmazott hosszabb távú orális fogamzásgátlás mint a magzati 21-es triszómia lehetséges kockázatcsökkentő tényezője idős anyai életkorban vállalt terhességben

Orvosi Hetilap ◽

10.1556/650.2018.31094 ◽

2018 ◽

Vol 159 (28) ◽

pp. 1146-1152

Author(s):

Dániel Horányi ◽

Lilla Éva Babay ◽

Balázs Győrffy ◽

Gyula Richárd Nagy

Keyword(s):

Down Syndrome ◽

Chromosomal Abnormality ◽

Trisomy 21 ◽

Maternal Age ◽

Genetic Disorder ◽

Advanced Maternal Age ◽

Oral Contraception ◽

Summary Report ◽

Meiotic Nondisjunction

Abstract: Down syndrome is the most common autosomal chromosomal abnormality. According to the classical interpretation, it is the result of meiotic nondisjunction. Its occurrence is more common in advanced maternal age. Despite intensive research, pathophysiology of this genetic disorder is not fully understood. According to recent studies, a different kind of mechanism may be found in the background of trisomy 21 than was previously considered. Based on the ovarian mosaicism model, the cause of trisomy 21 (or any common trisomy) is a segregation error of a chromosome in premeiotic mitosis. The cell entering meiosis will be an oocyte with preexisting trisomy, where its (so-called “secondary”) nondisjunction is essential. Maturation of the trisomic oocytes appears to fall behind the disomic oocytes, resulting in their relative accumulation in the ovaries as time progresses. The ratio of trisomic/disomic cells becomes less favorable in maternal maturity. If ovulation is inhibited – although the number of oocytes will continue to decline due to apoptosis – it can be assumed that the trisomic/disomic oocyte ratio remains more favorable with the progression of age. In our summary report, presenting and updating our previous data, we would like to propose that – according to ovarian mosaicism model – long-term oral contraception in the anamnesis may be beneficial in pregnancies with advanced maternal age. Orv Hetil. 2018; 159(28): 1146–1152.

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