FISH

SMALL SUPERNUMERARY MARKER CHROMOSOMES

-  sSMC -

BASICS - FIRST DESCRIPTION

 

When was the first sSMC described?

 

In 1961 Ilberry et al. {28} describe a 2 year old boy with epicanthic fold, slightly protuberant tongue who had a karyotype 47,XY,+mar[53]/46,XY[16]de novo. The sSMC was a "centric particle" of about the same size as 17p.

This paper was not well-recognized and thus, the work of Froland et al. {8} is often mentioned as first description of sSMC. The latter describe a boy with various congenital defects and a karyotype 47,XY,+mar; the sSMC is metacentric and of comparable size as #21 - and turned out to be a tetrasomy 18p{72}.
However, the case reported by Froland et al. (1963) was indeed only the third described sSMC-case, as in 1962 there was an additional report of Ellis et al. {106}.

 

References