Novel mutations of FOXC1 and PITX2 in patients with Axenfeld-Rieger malformations.
OBJECTIVE
To determine the prevalence of FOXC1 and PITX2 mutations and to assess clinical phenotypes in a cohort of German patients with Axenfeld-Rieger malformations.


METHODS
All coding exons of the FOXC1 and PITX2 genes were amplified by PCR from genomic DNA and subjected to direct DNA sequencing. Analysis of mutations in control subjects was performed by restriction fragment length polymorphism (RFLP) analysis.


RESULTS
Sequence variants were identified by DNA sequencing in 15 of 19 cases. Mutation screening identified four potentially pathogenic FOXC1 mutations causing amino acid substitutions (P79R, Y115S, G149D, and M161V) that were not present in 100 control subjects. In addition, two different 1-bp deletions causing a frameshift and subsequent premature stop codon were identified in two subjects. One patient harbored a FOXC1 nonsense mutation (S48X). Mutation screening also identified two potentially pathogenic PITX2 mutations (P64L and P64R) in two index patients that were excluded in 100 healthy control subjects.


CONCLUSIONS
The findings in the present study clearly demonstrate that FOXC1 and PITX2 mutations are responsible for a significant proportion of Axenfeld-Rieger malformations in Germany.
Weisschuh
Nicole
N
Molecular Genetics Laboratory, University Eye Hospital, Tübingen, Germany. nicole.weisschuh@uni-tuebingen.de
Dressler
Paul
P
Schuettauf
Frank
F
Wolf
Christiane
C
Wissinger
Bernd
B
Gramer
Eugen
E
D000595:Amino Acid Sequence; D000869:Anterior Eye Segment / Q000002:abnormalities*; D003062:Codon / Q000235:genetics; D004252:DNA Mutational Analysis; D005124:Eye Abnormalities / Q000235:genetics*; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics*; D005901:Glaucoma / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007429:Intraocular Pressure / Q000235:genetics; D007498:Iris / Q000002:abnormalities*; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics*; D000097577:Homeobox Protein PITX2
D003062:Codon; D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; D014157:Transcription Factors; D000097577:Homeobox Protein PITX2; C112743:FOXC1 protein, human