Estimates of the likelihood that a Down's syndrome child of unknown genotype is a consequence of an inherited translocation.
- 1 August 1980
- journal article
- research article
- Published by BMJ in Journal of Medical Genetics
- Vol. 17 (4) , 273-276
- https://doi.org/10.1136/jmg.17.4.273
Abstract
The proportions of Down''s syndrome livebirths associated with a Robertsonian translocation inherited from a carrier parent were estimated from data in the New York State Chromosome Registry [USA] and 2 previous publications. Indirect estimates were made in each 5 yr maternal age interval; these were derived from mutation rates for these translocations and maternal age specific prevalence rates in livebirths. The proportions diminished steadily with increasing maternal age. The ranges for the 7 maternal age groups from under 20 to 45 to 49 were: 1.1 to 2.8%, 1.0 to 2.7%, 0.7 to 1.8%, 0.5 to 1.3%, 0.2 to 0.4%, 0.05 to 0.1%, and 0.02 to 0.04%. Direct estimates from the observed data could only be attempted for 2 age groups, women under 30 yr and those 30 yr or more. For those under 30 the range in proportions was 0.9 to 1.9% and for those 30 and over, 0.2 to 0.4%. In general, the lowest proportions at any age were derived from New York State data and the highest from Japanese data.This publication has 5 references indexed in Scilit:
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