Cytogenetic Profile in 1,921 Cases of Trisomy 21 Syndrome

Flores-Ramirez, Francisco J.; Palacios-Guerrero, Claudia; García-Delgado, Constanza; Morales-Jiménez, Ariadna Berenice; Arias-Villegas, Christian; Cervantes, Alicia; Morán-Barroso, Verónica Fabiola

doi:10.1016/j.arcmed.2015.08.001

Cited by 24 publications

(16 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Over 1,200 cases were clinically diagnosed with Down syndrome, 86.4% of all patients had a standard T21 karyotype which is comparable with the frequencies identified in China (86.46%) [23], Albania (93.4%) [24], and Mexico (93.02%) [25] (Table 3). …”

Section: Discussionsupporting

confidence: 70%

Chromosomal Abnormalities in Patients with Intellectual Disability: A 21-Year Retrospective Study

et al. 2018

View full text Add to dashboard Cite

Background: Intellectual disability (ID) has been defined as a considerably reduced ability to understand new or complex information and to learn new skills. It is associated with life-long intellectual and adaptive functioning impairments that have a profound impact on individuals, families, and society. It affects about 3% of the general population. ID often comes out with other mental conditions like attention deficit, hyperactivity, and autism spectrum disorders (ASD), and it can be part of a malformation syndrome that affects other organs. It may be syndromic (S-ID) or non-syndromic (NS-ID). Objective: The aims of this study were to identify the profile of intellectually disable patients being referred for cytogenetic analysis in Morocco, to determine the prevalence of chromosomal abnormalities in a Moroccan group, and to compare the results with those of analogous studies from other countries. Participants: We included data from Moroccan patients with NS-ID and others with S-ID (mostly Down syndrome cases) who have been referred between 1996 and 2016. 1,626 patients were involved in this study, 1,200 were referred with a clinical diagnosis of Down syndrome, 37 were clinically diagnosed for ASD with ID, and 389 were suspected of NS-ID. Results: We identified 1,200 cases of Down syndrome. In 1,096 analyses (91.3%), a cytogenetic variant of trisomy 21 was identified: standard trisomy 21 in 1,037 cases (94.6%), a translocation in 34 cases (3.10%), and mosaicism in 25 cases (2.3%). The cytogenetic analysis among ASD with ID cases did not reveal any specific chromosomal abnormalities. The present study also shows that chromosomal abnormalities were present in 6.43% of the patients with NS-ID (25 abnormal karyotypes out of 389 NS-ID cases). Autosomal structural abnormalities were the largest proportion of chromosomal aberrations. Conclusion: The high rate of chromosomal abnormalities found in the Moroccan patients studied demonstrates the capital importance of cytogenetic evaluation in patients who show ID or any clinical development abnormality.

show abstract

Section: Discussionsupporting

confidence: 70%

Chromosomal Abnormalities in Patients with Intellectual Disability: A 21-Year Retrospective Study

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Down syndrome (DS) also known as trisomy 21 is the most chromosomal abnormality, with an incidence of 1 in every 1,000 to 1:1,100 infants (Flores‐Ramírez et al, ; Lukowskia, Milojevichb, & Ealesc, ; Papavassiliou, Charalsawadi, Rafferty, & Jackson‐Cook, ). DS is a genetic abnormality caused by the existence of additional copy or part of human chromosome 21 (Antonarakis & Epstein, ; Karmiloff‐Smith et al, ; Patterson, ; Ringman, Rao, Lu, & Cederbaum, ).…”

Section: Introductionmentioning

confidence: 99%

“…Less frequency mosaicism for trisomy 21 and translocation can also lead to DS (Bornstein et al, ; Ringman et al, ). Ninety to ninety‐five per cent of people affected with DS had an extra copy of entire chromosome 21 in all cells (Papavassiliou et al, ), and in 3%–5% of cases, mosaicism is the reason of DS resulted by a nondisjunction post‐zygotic incident (Flores‐Ramírez et al, ). Robertsonian translocations have been observed in four per cent of DS individuals in which chromosome 21 is translocated to another acrocentric chromosome.…”

Section: Introductionmentioning

confidence: 99%

“…Robertsonian translocations have been observed in four per cent of DS individuals in which chromosome 21 is translocated to another acrocentric chromosome. This translocations usually involve chromosome 14 or another chromosome 21 named cytogenetically der(14;21)(q10;q10) or rea (21;21) respectively (Flores‐Ramírez et al, ). The age of the mother is an important risk factor for the nondisjunction of chromosome 21, so DS occurs more frequently in older mothers (Patterson, ; Sherman, Freeman, Allen, & Lamb, ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A male Down syndrome with two normal boys: Cytogenetic, paternity and andrological investigations

Jazayeri

Gorjizadeh²

2020

Andrologia

View full text Add to dashboard Cite

Down syndrome is the most common autosomal chromosome anomaly with several medical abnormalities and intellectual disability, occurring in about of 1:1,000 to 1:1,100 infants. Many pregnancies in women with Down syndrome produce children both with normal and with trisomy 21, whereas males are infertile. However, Down syndrome males are not always infertile and this is not global. Here we reported a 36‐year‐old man with proved nonmosaic trisomy 21 fathered two normal boys. Paternity analysis using 26 microsatellite loci confirmed that Down syndrome male is the biological father of his two normal boys. Serum LH, FSH, testosterone and 17‐OH progesterone were all in the normal range in this father with Down syndrome. To the best of our knowledge, this is the second report of one man with Down syndrome who has two normal children in the world. The current study not only supports the rare evidence of the fertility of males with Down syndrome but also highlights the caution in advising people responsible for the care of adults with this condition about possible fertility and transmission of sexual diseases as well.

show abstract

“…Only 5% of patients have translocation of chromosome 21 to one of the acrocentric chromosomes, usually chromosome 14 or 21. In very few cases of DS, there is detectable mosaicism for a trisomic and a normal cell line [5,6].…”

Section: Introductionmentioning

confidence: 99%

The demographic data and the high frequency of chromosome/chromatid breaks as biomarkers for genome integrity have a role in predicting the susceptibility to have Down syndrome in a cohort of Egyptian young-aged mothers

El-Attar

Issa

Mahrous

2019

Egypt J Med Hum Genet

View full text Add to dashboard Cite

Background Down syndrome (DS) is a common numerical chromosome disorder that has its burden on both family and community. The well-known risk factor for chromosome 21 nondisjunction is advanced maternal age which failed to explain the occurrence of Down syndrome born to mothers less than 35 years. This study aimed to assess the effect of demographic data (consanguinity, residency area, and socioeconomic state) and chromosome/chromatid breaks as biomarkers for genome integrity on the susceptibility of young mothers to have a child with Down syndrome. Results Fifty mothers with a history of at least one DS pregnancy before the age of 35 were compared to 50 control mothers. There was a significant increase in DS births in consanguineous parents (46%) compared to 20% in non-consanguineous ones (OR = 3.40; 95% CI = 1.4–8.20, P = 0.006). Young mothers with DS children were more likely to be from rural areas (60%) than urban areas (40%) (OR = 2.66; 95%, CI = 1.18–5.98, P = 0.017) and of a low socioeconomic status (62%) rather than a high socioeconomic status (38%) (OR = 3.80; 95%, CI = 1.65–8.74, P = 0.001). Chromosome/chromatid breaks were detected in 76% of DS young mothers and 32% of control mothers (P < 0.001). There was an odds ratio of chromatid breaks of 8.50 (3.411–21.17) and chromosome breaks of 3.93 (1.40–11.05) with significant difference between the studied groups (P < 0.001 and P = 0.009 respectively). Conclusion In addition to advanced maternal age, consanguinity, residency in rural areas, and low socioeconomic status could be considered as possible risk factors for Down syndrome. The high frequency of chromosome/chromatid breaks in young mothers with a previous history of DS children highlights the impact of genome integrity on the tendency to chromosome 21 nondisjunction. These findings are valuable in predicting having a Down syndrome baby and providing proper genetic counseling for high-risk families.

show abstract

Cytogenetic Profile in 1,921 Cases of Trisomy 21 Syndrome

Cited by 24 publications

References 19 publications

Chromosomal Abnormalities in Patients with Intellectual Disability: A 21-Year Retrospective Study

Chromosomal Abnormalities in Patients with Intellectual Disability: A 21-Year Retrospective Study

A male Down syndrome with two normal boys: Cytogenetic, paternity and andrological investigations

The demographic data and the high frequency of chromosome/chromatid breaks as biomarkers for genome integrity have a role in predicting the susceptibility to have Down syndrome in a cohort of Egyptian young-aged mothers

Contact Info

Product

Resources

About