Chromosomal Translocations in Mongolism and in Normal Relatives

Penrose, L. S.; Ellis, James E.; Delhanty, JD

doi:10.1016/s0140-6736(60)92846-4

Cited by 151 publications

(31 citation statements)

References 5 publications

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“…It is now more than 75 years since the maternal age effect in Down syndrome (DS) was first discovered (Penrose 1933(Penrose , 1934 and 50 years since the genetic background in DS involving extra chromosome 21 material was identified (Book et al 1959, Ford et al 1959, Jacobs et al 1959, Lejeune et al 1959, Penrose et al 1960, Polani et al 1960. In the interim it has become abundantly clear that the origin of the most common type of DS associated with a free extra chromosome 21 (T21) differs from the more rare types that are dependent on extra chromosome 21 material caused by a structural chromosome rearrangement.…”

Section: Down Syndrome 50 Years On: What Do We Know About the Origin?mentioning

confidence: 99%

On the origin of the maternal age effect in trisomy 21 Down syndrome: the Oocyte Mosaicism Selection model

Hultén

Patel²,

Jonasson³

et al. 2010

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We have recently documented that trisomy 21 mosaicism is common in human foetal ovaries. On the basis of this observation we propose that the maternal age effect in Down syndrome (DS) is caused by the differential behaviour of trisomy 21 in relation to disomy 21 oocytes during development from foetal life until ovulation in adulthood. In particular, we suggest that trisomy 21 oocytes, lagging behind those that are disomic, may escape the timed pruning of the seven million in foetal life to the 300-400 finally selected for ovulation. The net effect of this preferential elimination will be an accumulation of trisomy 21 oocytes in the ovarian reserve of older women. We here highlight the implications of this Oocyte Mosaicism Selection (OMS) model with respect to the prevalent view that the maternal age effect is complex, dependent on many different biological and environmental factors. We examine conclusions drawn from recent largescale studies in families, tracing DNA markers along the length of chromosome 21q between parents and DS children, in comparison to the OMS model. We conclude that these family linkage data are equally compatible with the maternal age effect originating from the accumulation of trisomy 21 oocytes with advancing maternal age. One relatively straightforward way to get to grips with what is actually going on in this regard would be to compare incidence of trisomy 21 oocytes (and their pairing configurations) in foetal ovaries with that in oocytes at the meiosis I stage from adult women.

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Section: Down Syndrome 50 Years On: What Do We Know About the Origin?mentioning

confidence: 99%

On the origin of the maternal age effect in trisomy 21 Down syndrome: the Oocyte Mosaicism Selection model

Hultén

Patel²,

Jonasson³

et al. 2010

Reproduction

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“…Moreover, the abnormality is specific in that a particular chromosome, or part of a particular chromosome, is present in triplicate rather than the normal twice. Severa4l mongol patients with this and other similar abnormal chromosome complexes have been described , Carter et al 1960, Penrose et al 1960 (Clarke et al 1961).…”

mentioning

confidence: 71%

“…Although it may be suggested that the chromosome abnormalities found in mongolism are the result of mongolism, not the cause, the pedigree described above and similar pedigrees (Penrose et al 1960, Hamerton et al 1961 show that this is not so. The abnormal chromosome, which may differ in detail in different families, is already present, in balanced form, in a physically normal parent.…”

Section: Clinical Features and Cytologymentioning

confidence: 90%

Chromosome Abnormalities

1963

N Engl J Med

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“…Other papers on Down syndrome from the groups of Jacobs, Böök, Polani, and Harnden followed in 1959, as did papers on human sex chromosome aberrations, including 47,XXX (76) and XX/XXY mosaic (59). In the following year we reported two patients with 48,XXXY (46), and trisomies 13 and 18 and translocation Down syndrome were also added to the list of discoveries (11,26,102,103,108).…”

Section: Early Chromosome Studies and Sex Determinationmentioning

confidence: 98%

Putting Medical Genetics into Practice

Ferguson-Smith

2011

Annu. Rev. Genom. Hum. Genet.

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This article describes a fragment of history on the growing impact of genetics on the practice of medicine over 50 years, as experienced by a medical geneticist who helped to provide services to patients at risk of genetic disorders. It is a personal account influenced by a fascination with chromosomes that has drawn him into many studies, including sex determination, gene discovery, fetal diagnosis, phylogenomics, and karyotype evolution.

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Chromosomal Translocations in Mongolism and in Normal Relatives

Cited by 151 publications

References 5 publications

On the origin of the maternal age effect in trisomy 21 Down syndrome: the Oocyte Mosaicism Selection model

On the origin of the maternal age effect in trisomy 21 Down syndrome: the Oocyte Mosaicism Selection model

Chromosome Abnormalities

Putting Medical Genetics into Practice

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