Genetic linkage studies are among the most popular methods of study to look at the mechanism of this<unk> . Genetic linkage studies have found to localize genetic loci for autosomal dominant forms of<unk>  to chromosome 2p21-p22 (indicative of<unk> 1) and chromosome 5q13-q22 (indicative of<unk> 2). Chromosome 2p21-p22 has been refined to an interval of ~2.3 Mb to construct an integrated physical and genetic map of the 16 genes interval. Here, a mutation is found in sequencing these 16 genes. There is an insertion of a cytosine between nucleotides 126,142 and 126,143 in codon 1083 of the SOS1 gene, meaning there is a mutation in SOS1. This causes a problem because SOS1 introduces a frameshift mutation and creates a premature stop codon. Also, it can segregate over generations, most commonly four. Once it causes a premature stop codon, the chromosome loses four important proline-rich SH-3 binding domains in the carboxyl-terminal region of the SOS1 protein. As a result, the N-terminal amino acids for SOS1 is fused into a 22–amino acid carboxyl terminus. Researchers claim that this mutation in the SOS1 gene is a probable primary cause of this disease but limited information supports the mechanism of this claim.
Hereditary gingival fibromatosis
Connective tissue nevus
Acral fibrokeratoma
Gingival fibromatosis with hypertrichosis
Congenital melanocytic nevus
Basal cell adenoma
Dermal cylindroma
Hydrocarbon keratosis