Mutations of the SH3BP2 gene in 2 families of cherubism.
OBJECTIVE
Cherubism is a rare autosomal dominant syndrome characterized by abnormal bone tissue in the lower part of the face. Mutations in the gene coding for SH3BP2 have been identified in about 80% of people with cherubism. The aim of this study was to determine whether a mutation  in the SH3BP2 gene was the molecular basis of cherubism in two unrelated families.


METHODS
Two cases of the aggressive form of Cherubism were described in two Turkish families with extensive bilateral swelling in the mandible, typical pathological features and familial history. Genomic  DNA was extracted from six affected and three unaffected individuals from two families, and mutations in the SH3BP2 were detected by PCR, and direct DNA sequencing was carried out.


RESULTS
In the first family, a missense mutation Arg415Gln was found in exon 9 of the SH3BP2 in all affected  individuals. The unaffected individuals did not have this mutation. In the second family, another missense mutation Pro418Thr was identified in exon 9 of the SH3BP2 in the patient and his mother with cherubism.


CONCLUSIONS
We detected the point mutations in the SH3BP2 gene in the patients  with multiple affected individuals. Genotype-phenotype association studies in individuals with cherubism are necessary to provide important knowledge about molecular mechanisms of the disease.
Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey. ebtuna@istanbul.edu.tr
Elif Bahar
EB
Tuna
Takehiko
T
Shimizu
Figen
F
Seymen
Mine
M
Yildirim
Koray
K
Gencay
Takahide
T
Maeda
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D001483:Base Sequence; D002636:Cherubism / Q000235:genetics*; D002648:Child; D017931:DNA Primers; D006801:Humans; D008297:Male; D020125:Mutation, Missense; D014429:Twins, Dizygotic
D048868:Adaptor Proteins, Signal Transducing; D017931:DNA Primers; C109073:SH3BP2 protein, human