FISH studies in a patient with sporadic aniridia and t(7;11) (q31.2;p13).
A 2 year old female presenting with bilateral sporadic aniridia was found to have an apparently balanced reciprocal translocation with a chromosome 11 breakpoint within band p13. Fluorescence in situ hybridisation (FISH) studies with distal 11p13 specific cosmids showed that the chromosome 11 breakpoint lay between the aniridia (PAX6) locus and a region approximately 100 kb distal to PAX6 defined by the cosmid FO2121. Although this patient did not have a detectable deletion within PAX6, her aniridia may have resulted from a disruption of the distal chromatin domain containing either enhancers or regulators for PAX6. This case may therefore be another example of aniridia caused by a position effect as recently described in two familial aniridia patients in which the phenotype cosegregated with chromosome abnormalities with 11p13 breakpoints.
Crolla
J A
JA
Wessex Regional Genetics Laboratory, Salisbury District Hospital, Wiltshire, UK.
Cross
I
I
Atkey
N
N
Wright
M
M
Oley
C A
CA
D015783:Aniridia / Q000235:genetics*; D002675:Child, Preschool; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics*; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics*; D003582:Cytogenetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D014178:Translocation, Genetic / Q000235:genetics*