Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1999-2-22
pubmed:abstractText
Defects in lateralization can be studied from the stance of populations, the individual, or the systems of organs within each individual. Unfortunately, and confusingly, the same terms are being applied to each of these situations, but inevitably with different meanings. Thus, there is presently no consensus on how we should use terms such as "heterotaxy" and "situs ambiguus". By far the least ambiguous use of these words is encountered when they are applied to the organs. In fact, each system of organs can accurately and simply be described in terms of its left-right morphology. All those organs which are paired then can be described, when interpreted on the basis of their intrinsic morphology, as being usually arranged, mirror-imaged, or as showing left or right isomerism. Within the heart, these changes are seen only in the atrial segment. The criterion for distinction of rightness or leftness within the atrial segment is the extent of the pectinate muscles relative to the atrioventricular junction. Application of this criterion permits unequivocal recognition of symmetry as opposed to lateralization. The same holds good for the other organs. Within any individual organ, therefore, the situation is neither ambiguous nor heterotaxic. Instead, it is lateralised or symmetrical. Within the individual, in contrast, there may well be discrepancies in the expected disposition of the systems of organs which produces potential ambiguity. To dispel this ambiguity, it is necessary to provide a full catalogue. For example, persons with otherwise normally arranged organs may have left bronchial isomerism. Other persons may have discordance between the thoracic organs, which are usually arranged, and the abdominal organs, which are mirror-imaged, but no evidence of isomerism. Within the population, however, we are unaware of any genetically or environmentally induced syndrome in which all individuals show evidence of mirror-imagery, or of isomerism, or of specific discordance between the systems. In fact, all known syndromes encompass all types of defective lateralization. When attempting to identify the genetic mechanisms for production of the syndromes, therefore, it could be positively misleading to attempt to separate isomerism from other perceived forms of"heterotaxy". Our preference is to consider any deviation from the usual arrangement as heterotaxy, and to specify the specific arrangement of the organs within each malformed individual.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1047-9511
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
512-31
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Defective lateralisation in children with congenitally malformed hearts.
pubmed:affiliation
Paediatrics, Royal Brompton Campus, National Heart and Lung Institute, Imperial College School of Medicine, London, United Kingdom.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't