Small supernumerary maker chromosome (sSMC) is a type of structurally abnormal chromosome. In order to identify the origin, morphology and other characteristics of sSMCs in children with mos 45,X/46,X,+mar karyotype, 17 patients (16 females and 1 male) were analyzed. All patients underwent general physical examination, gonadal imaging and molecular cytogenetic analyses, including Giemsa banding...

The regular chromosomal complement of maize consists of 20 chromosomes. These are known as the A set and are invariably present in this number in all normal diploid plants. Heteropycnotic regions known as "knobs" are found in characteristic positions on the different A chromosomes, although the number of knobs varies greatly in different strains. Knobless races are known, while others have as m...

HE supernumeraries, or B chromosomes, of the mealy bug, Pseudococcus obscurus, have been shown to undergo preferential segregation both in oogenesis and in spermatogenesis (NUR 1962a). In a female with two supernumeraries, they do not pair during the first meiotic division but usually pair and segregate regularly in the second division. However, when one or an odd number is present the unpaired...

We report a case of isodicentric chromosome 15 (idic(15) chromosome), the presence of which resulted in uncontrolled seizures, including epileptic spasms, tonic seizures, and global developmental delay. A 10-month-old female infant was referred to our pediatric neurology clinic because of uncontrolled seizures and global developmental delay. She had generalized tonic-clonic seizures since 7 mon...

Fifteen patients presenting with mosaic or non-mosaic karyotypes containing a distamycin-DAPI negative de novo or familial supernumerary marker chromosome were studied with non-isotopic in situ hybridisation using a library of alphoid centromere specific and satellite II/III probes. The in situ hybridisation studies showed that seven markers were derived from satellited autosomes (three chromos...

We report a patient with cat eye syndrome and interrupted aortic arch type B, a typical finding in the 22q11.2 deletion syndrome. Chromosomal analysis and fluorescent in situ hybridization (FISH) showed a supernumerary bisatellited isodicentric marker chromosome derived from chromosome 22. The segment from 22pter to 22q11.2 in the supernumerary chromosome found in our patient does not overlap w...