[Clinical diagnosis of Down's syndrome based on 11 signs. Epidemiological analysis of the specificity of the studied signs].

OBJECTIVE

Down's syndrome (trisomy 21) is the most frequent viable chromosomal abnormality, as well as the only one that can be postnatally diagnosed on the basis of a series of clinical signs. However, none is specific by itself. It is generally accepted that the diagnosis can be made on the basis of the concurrence of a large number of signs. Nevertheless, since most of the clinical signs can be observed in the general population, each one of them has a different level of specificity for the diagnosis of Down's syndrome, depending on its frequency in every population.

PATIENTS AND METHODS

We have studied in our population the frequency and specificity of 11 signs for the diagnosis of Down's syndrome by using data from the Spanish Collaborative Study of Congenital Malformations (ECEMC).

RESULTS

The analysis of the 11 signs shows great specificity for some of them and for the concurrence of four or more.

CONCLUSIONS

We consider that although the final diagnosis will come from chromosomal analysis, it can be very useful to have indicators available for the clinical diagnosis at birth. This is extremely important so that the corresponding chromosomal analysis is immediately performed, which will result in early and correct information to the parents.