A Mutation in the SOS1 Gene Causes Hereditary Gingival Fibromatosis Type 1
Hereditary gingival fibromatosis (HGF) is a rare, autosomal dominant form of gingival overgrowth. Affected individuals have a benign, slowly progressive, nonhemorrhagic, fibrous enlargement of the oral masticatory mucosa. Genetic loci for autosomal dominant forms of HGF have been localized to chromo...
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Published in | American journal of human genetics Vol. 70; no. 4; pp. 943 - 954 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Chicago, IL
Elsevier Inc
01.04.2002
University of Chicago Press The American Society of Human Genetics |
Subjects | |
Online Access | Get full text |
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Summary: | Hereditary gingival fibromatosis (HGF) is a rare, autosomal dominant form of gingival overgrowth. Affected individuals have a benign, slowly progressive, nonhemorrhagic, fibrous enlargement of the oral masticatory mucosa. Genetic loci for autosomal dominant forms of HGF have been localized to chromosome 2p21-p22 (HGF1) and chromosome 5q13-q22 (HGF2). To identify the gene responsible for HGF1, we extended genetic linkage studies to refine the chromosome 2p21-p22 candidate interval to ∼2.3 Mb. Development of an integrated physical and genetic map of the interval identified 16 genes. Sequencing of these genes, in affected and unaffected HGF1 family members, identified a mutation in the
Son of sevenless–1 (
SOS1) gene in affected individuals. In this report, we describe the genomic structure of the
SOS1 gene and present evidence that insertion of a cytosine between nucleotides 126,142 and 126,143 in codon 1083 of the
SOS1 gene is responsible for HGF1. This insertion mutation, which segregates in a dominant manner over four generations, introduces a frameshift and creates a premature stop codon, abolishing four functionally important proline-rich SH3 binding domains normally present in the carboxyl-terminal region of the SOS1 protein. The resultant protein chimera contains the wild-type SOS1 protein for the N-terminal amino acids 1–1083 fused to a novel 22–amino acid carboxyl terminus. Similar SOS1 deletion constructs are functional in animal models, and a transgenic mouse construct with a comparable SOS1 chimera produces a phenotype with skin hypertrophy. Clarification of the functional role of this SOS1 mutant has implications for understanding other forms of gingival fibromatosis and corrective gingival-tissue management. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0002-9297 1537-6605 |
DOI: | 10.1086/339689 |