Exclusion of PITX2 mutations as a major cause of CHARGE association.
CHARGE is a nonrandom association of ocular coloboma, congenital heart defects, atresia of the choanae, retarded growth and development, genital hypoplasia, and ear anomalies including deafness. The cause of CHARGE remains unknown; however, there is considerable evidence of an underlying genetic basis, as discussed by Tellier et al. [1996: Clin Genet 50:548-550; 1998: Am J Med Genet 76:402-409] and by Martin et al. [2001: Am J Med Genet 99:115-119]. Based on the ocular, cardiac, and craniofacial expression pattern of Pitx2, a homeodomain transcription factor, and the pleiotropic effects of loss of PITX2 function in both mouse and human, we hypothesized that PITX2 mutations may contribute to the multiple phenotypic anomalies present in CHARGE individuals. By direct sequencing of DNA from 29 individuals with CHARGE, we did not identify any mutations in PITX2. We did, however, identify two PITX2 sequence polymorphisms. Large deletions of PITX2 were excluded in most patients by heterozygosity in at least one of several polymorphic markers near the PITX2 locus. Together, these data indicate that PITX2 mutations are unlikely to be a major contributing cause of the multiple anomalies present in individuals with CHARGE.
Martin
Donna M
DM
Department of Pediatrics, The University of Michigan Medical School, Ann Arbor 48109-0688, USA. donnamm@umich.edu
Probst
Frank J
FJ
Fox
Sharon E
SE
Schimmenti
Lisa A
LA
Semina
Elena V
EV
Hefner
Margaret A
MA
Belmont
John W
JW
Camper
Sally A
SA
D000015:Abnormalities, Multiple / Q000235:genetics*; D002754:Choanal Atresia / Q000235:genetics; D003103:Coloboma / Q000235:genetics; D004252:DNA Mutational Analysis; D003638:Deafness / Q000235:genetics; D004423:Ear / Q000002:abnormalities; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005835:Genitalia / Q000002:abnormalities; D006130:Growth Disorders / Q000235:genetics; D006330:Heart Defects, Congenital / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008297:Male; D009687:Nuclear Proteins; D010641:Phenotype; D011110:Polymorphism, Genetic; D013577:Syndrome; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology; D000097577:Homeobox Protein PITX2
D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D000097577:Homeobox Protein PITX2