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Brazilian Journal of Genetics

Print version ISSN 0100-8455

Braz. J. Genet. vol.19 no.4 Ribeirão Preto  1996

http://dx.doi.org/10.1590/S0100-84551996000400020 

Full text in pdf format

 

Maternal age and Down syndrome in Southeastern Brazil

 

 

Bernardo BeiguelmanI; Henrique KriegerII; Luciana Marques da SilvaI

IDepartamento de Genética Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Caixa Postal 6111,13081-970 Campinas, SP, Brasil. Send correspondence to B.B.
IIDepartamento de Parasitologia, Instituto de Ciências Biomédicas, USP, São Paulo, SP, Brasil

 

 


ABSTRACT

The proportion of maternal-age-independent patients estimated among 200 Brazilian Down syndrome children (59.6%) was significantly larger than that of maternal-age-dependent cases (40.4%). The latter proportion is the smallest observed in pertinent literature and due basically to the low mean maternal age of the population analyzed. Based on the remarkable correlation (r = 0.95) between the proportion of maternal-age-dependent patients and the mean maternal age of the general population, a simple predictive equation to estimate the proportion of maternal-age-dependent Down syndrome patients based on the mean maternal age of the general population is suggested in situations where reliable data on the incidence of this syndrome according to maternal age is not available.

Keywords: maternal age; Down syndrome; Southeastern Brazil.


 

 

REFERENCES

Beiguelman, B. (1982). Citogenética Humana. Guanabara Koogan, Rio de Janeiro.         [ Links ]

Beiguelman, B. and Villarroel-Herrera, H.O. (1993). Factors influencing the decline of twinning incidence in a southeastern Brazilian population. Rev. Bras. Genet. 16: 793-801.         [ Links ]

Hook, E.B. and Chambers, G.M. (1977). Estimated rates of Down syndrome in live births by one year maternal age intervals for mothers aged 20-49 in a New York State study - implications of the risk figures for genetic counseling and cost-benefit analysis of prenatal diagnosis programs. Birth Defects: Original Article Series, 13, Number 3A: 123-141.         [ Links ]

Hook, E.B. and Fabia, J.J. (1978). Frequency of Down syndrome in livebirths by single-year maternal age interval: results of Massachusetts study. Teratology 17: 223-228.         [ Links ]

Hook, E.B. and Lindsjö, A. (1978). Down syndrome in live births by single year maternal age interval in a Swedish study: comparison with results from a New York State study. Am. J. Hum. Genet. 30: 19-27.         [ Links ]

Lamson, S.H. and Hook, E.B. (1980). A simple function for maternal-age-specific rates of Down syndrome in the 20-to-49-year age range and its biological implications. Am. J. Hum. Genet. 32: 743-753.         [ Links ]

Lamson, S.H. and Hook, E.B. (1981). Comparison of mathematical models for the maternal age dependence of Down's syndrome rates. Hum. Genet. 59: 232-234.         [ Links ]

Parsons, P.A. (1964). Parental age and the offspring. Q. Rev. Biol. 39: 258-275.         [ Links ]

Penrose, L.S. (1954). Mongolian idiocy (mongolism) and maternal age. Ann. N.Y. Acad. Sci. 57: 494-502.         [ Links ]

Penrose, L.S. (1961). Parental age and non-disjunction. In: Human Chromosomal Abnormalities (Davidson, W.M. and Robertson Smith, D., eds.). Staples Press, London, pp. 116-122.         [ Links ]

Renwick, D.H.G., Miller, J.R. and Paterson, D. (1964). Estimates of incidence and prevalence of mongolism and of congenital heart disease in British Columbia. Can. Med. Assoc. J. 91: 365-371.         [ Links ]

Sutherland, G.R., Clisby, S.R., Bloor, G. and Carter, R.F. (1979). Down's syndrome in South Australia. Med. J. Austr. 2: 58-61.        [ Links ]