H. Joenje et al., Complementation analysis in Fanconi anemia: Assignment of the reference FA-H patient to group A, AM J HU GEN, 67(3), 2000, pp. 759-762
Citations number
20
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Molecular Biology & Genetics
Fanconi anemia (FA) is an autosomal recessive disorder with diverse clinica
l symptoms and extensive genetic heterogeneity. Of eight FA genes that have
been implicated on the basis of complementation studies, four have been id
entified and two have been mapped to different loci; the status of the gene
s supposed to be defective in groups B and H is uncertain. Here we present
evidence indicating that the patient who has been the sole representative o
f the eighth complementation group (FA-H) in fact belongs to group FA-A. Pr
evious exclusion from group A was apparently based on phenotypic reversion
to wild-type rather than on genuine complementation in fusion hybrids. To a
void the pitfall of reversion, future assignment of patients with FA to new
complementation groups should conform with more-stringent criteria. A new
group should be based on at least two patients with FA whose cell lines are
excluded from all known groups and that fail to complement each other in f
usion hybrids, or, if only one such cell line were available, on a new comp
lementing gene that carries pathogenic mutations in this cell line. On the
basis of these criteria, the current number of complementation groups in FA
is seven.