It may be hereditary and parents may be mosaic for the marker chromosome but show no phenotypic symptoms of the syndrome.

It was described in association with a small marker chromosome in 1965.

B chromosomes are not to be confused with marker chromosomes or additional copies of normal chromosomes as they occur in Trisomies.

Second, the tumor karyotes is aneuploid but has characteristic marker chromosomes in all tumors collected in different geographic regions.

The extra chromosome is rarely found in mosaic state, i.e. some of the cells carry the marker chromosome.

More recently-evolved strains have an additional mutant marker chromosome, for a total of fourteen chromosomes.

A marker chromosome (mar) is a structurally abnormal chromosome in which no part can be identified.

A difficult situation arises when a marker chromosome is found on a prenatal study such as amniocentesis.

Chromosome 15 is the most frequently involved chromosome in cases of autism with supernumerary marker chromosomes.

These small supernumerary marker chromosomes can originate from any of the 24 different human chromosomes.