PMID- 15292587
OWN - NLM
STAT- MEDLINE
DCOM- 20050204
LR  - 20061115
IS  - 1424-859X (Electronic)
IS  - 1424-8581 (Linking)
VI  - 106
IP  - 2-4
DP  - 2004
TI  - Human supernumeraries: are they B chromosomes?
PG  - 165-72
AB  - In humans, the presence of supernumerary chromosomes is an unusual phenomenon, 
      which is often associated with developmental abnormalities and malformations. In 
      contrast to most animal and plant species, the extensive knowledge of the human 
      genome and the ample set of molecular and cytogenetic tools available have 
      permitted to ascertain not only that most human supernumerary chromosomes (HSCs) 
      derive from the A chromosome set, but also the specific A chromosome from which 
      most of them arose. These extra chromosomes are classified into six types on the 
      basis of morphology and size. There are both heterochromatic and euchromatic 
      HSCs, the latter being more detrimental. Most are mitotically stable, except some 
      producing individual mosaicism. No information is available on the HSC 
      transmission rate since extensive familial studies are not usually performed 
      generally because of death of the relatives or lack of cooperation. The main B 
      chromosome property failing in HSCs seems to be their population spread as 
      polymorphisms, since most HSCs seem to correspond to extra A chromosomes or 
      centric fragments spontaneously arisen in the analysed individual or one of 
      his/her parents. However, we cannot rule out at this moment, that more intensive 
      studies on population distribution and frequency of those HSCs most closely 
      resembling B chromosomes (i.e. those heterochromatic and thus less detrimental) 
      would reveal possible HSCs polymorphisms. Although HSCs cannot be considered B 
      chromosomes, some of them might be a source for future B chromosomes. The best 
      candidates would be heterochromatic HSCs, which might manage to drive in either 
      sex. To ascertain this possibility, research on inheritance and population 
      studies would be very helpful in combination with the powerful cytogenetic and 
      molecular tools available for our species.
CI  - Copyright 2004 S. Karger AG, Basel
FAU - Fuster, C
AU  - Fuster C
AD  - Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma 
      de Barcelona, Bellaterra, Spain.
FAU - Rigola, M A
AU  - Rigola MA
FAU - Egozcue, J
AU  - Egozcue J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Review
PL  - Switzerland
TA  - Cytogenet Genome Res
JT  - Cytogenetic and genome research
JID - 101142708
SB  - IM
MH  - Chromosomes, Human/*genetics
MH  - Humans
RF  - 69
EDAT- 2004/08/05 05:00
MHDA- 2005/02/05 09:00
CRDT- 2004/08/05 05:00
PHST- 2003/09/11 00:00 [received]
PHST- 2004/01/19 00:00 [accepted]
PHST- 2004/08/05 05:00 [pubmed]
PHST- 2005/02/05 09:00 [medline]
PHST- 2004/08/05 05:00 [entrez]
AID - 79283 [pii]
AID - 10.1159/000079283 [doi]
PST - ppublish
SO  - Cytogenet Genome Res. 2004;106(2-4):165-72. doi: 10.1159/000079283.