Two missense mutations in the IRF6 gene in two Japanese families with Van der Woude syndrome.
Van der Woude syndrome (VWS) is a common autosomal dominant disorder with cleft lip and/or palate and lower lip pits. Its prevalence is estimated to be 1/33,600 in the Finnish Population, and 1/47,813 in the Japanese. We performed mutation analysis of the IRF6 gene by direct sequencing in 2 unrelated Japanese families that consist of a total of 3 affected members with cleft lip and palate associated with lower lip pits. Consequently, we found novel base substitutions, 25C>T, in IRF6-exon 3 in a boy, his mother, and his phenotypically normal maternal grandmother in one of the families. A known mutation, 250C>T, was identified in exon 4 of a girl and her unaffected father in the other family. The same mutations were never observed among 190 healthy Japanese. The results indicate incomplete penetrance and variable expressivity in the families. Because 25C>T and 250C>T predict to lead to R9W and R84C substitutions, respectively, at the most conserved DNA binding domain of IRF6, and because arginine at positions 9 and 84 is highly conserved among IRFs, the 2 mutations may lead to abolish the DNA binding activity in the developing craniofacial region. To our knowledge, this is the first report of IRF6 mutations observed in Japanese VWS patients.
Department of Oral and Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Japan.
Noriko
N
Matsuzawa
Koh-Ichiro
K
Yoshiura
Junichiro
J
Machida
Tomoyasu
T
Nakamura
Teruyuki
T
Niimi
Hiroo
H
Furukawa
Tetsuro
T
Toyoda
Nagato
N
Natsume
Kazuo
K
Shimozato
Norio
N
Niikawa
D000595:Amino Acid Sequence / Q000235:genetics; D044466:Asian People; D016022:Case-Control Studies; D002971:Cleft Lip / Q000235:genetics*; D002972:Cleft Palate / Q000235:genetics*; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D050835:Interferon Regulatory Factors; D008297:Male; D020125:Mutation, Missense / Q000235:genetics*; D010375:Pedigree; D013577:Syndrome; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; C109803:IRF6 protein, human; D050835:Interferon Regulatory Factors; D014157:Transcription Factors