Mutations in the newly identified RAX regulatory sequence are not a frequent cause of micro/anophthalmia.
OBJECTIVE
Microphthalmia and anophthalmia are at the severe end of the spectrum of abnormalities in ocular development. A few genes (SOX2, OTX2, RAX, and CHX10) have been implicated in isolated micro/anophthalmia, but causative mutations of these genes explain less than a quarter of these developmental defects. A specifically conserved SOX2/OTX2-mediated RAX expression regulatory sequence has recently been identified. We postulated that mutations in this sequence could lead to micro/anophthalmia, and thus we performed molecular screening of this regulatory element in patients suffering from micro/anophthalmia.


METHODS
Fifty-one patients suffering from nonsyndromic microphthalmia (n = 40) or anophthalmia (n = 11) were included in this study after negative molecular screening for SOX2, OTX2, RAX, and CHX10 mutations. Mutation screening of the RAX regulatory sequence was performed by direct sequencing for these patients.


RESULTS
No mutations were identified in the highly conserved RAX regulatory sequence in any of the 51 patients.


CONCLUSIONS
Mutations in the newly identified RAX regulatory sequence do not represent a frequent cause of nonsyndromic micro/anophthalmia.
Chassaing
Nicolas
N
Vigouroux
Adeline
A
Calvas
Patrick
P
D000853:Anophthalmos / Q000235:genetics*; D005136:Eye Proteins / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008850:Microphthalmos / Q000235:genetics*; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics*
D005136:Eye Proteins; D018398:Homeodomain Proteins; C486393:RAX protein, human; D014157:Transcription Factors