Stockton et al. (2000) studied a family segregating a seemingly unique form of oligodontia in an autosomal dominant manner. The affected individuals had normal primary dentition but lacked most permanent molars. Some individuals also lacked maxillary and/or mandibular ... Stockton et al. (2000) studied a family segregating a seemingly unique form of oligodontia in an autosomal dominant manner. The affected individuals had normal primary dentition but lacked most permanent molars. Some individuals also lacked maxillary and/or mandibular second premolars as well as mandibular central incisors. Frazier-Bowers et al. (2002) described a large family with autosomal dominant oligodontia. Affected individuals showed predominantly molar oligodontia but it was not limited to posterior teeth. Lammi et al. (2003) described a Finnish family segregating autosomal dominant oligodontia with a distinct phenotype involving missing premolars, canines, and incisors in addition to permanent molars, as well as reduced size of both deciduous and permanent teeth. Several second premolars were missing, even though the neighboring first molars were present. Mostowska et al. (2006) described a 3-generation family with severe autosomal dominant oligodontia. Those affected lacked all permanent molars, second premolars, and mandibular central incisors.
Kim et al. (2006) analyzed the pattern of tooth agenesis in several kindreds with defined MSX1 and PAX9 mutations. They found that the probability of missing a particular type of tooth is always bilaterally symmetrical, but differences exist ... Kim et al. (2006) analyzed the pattern of tooth agenesis in several kindreds with defined MSX1 and PAX9 mutations. They found that the probability of missing a particular type of tooth is always bilaterally symmetrical, but differences exist between the maxilla and mandible. MSX1-associated tooth agenesis (STHAG1; 106600) typically includes missing maxillary and mandibular second premolars and maxillary first premolars. The most distinguishing feature of MSX1-associated tooth agenesis is the frequent (75%) absence of maxillary first premolars, whereas the most distinguishing feature of PAX9-associated tooth agenesis is the frequent (over 80%) absence of maxillary and mandibular second molars.
Nieminen et al. (1995) excluded involvement of the MSX1 (142983) and MSX2 (123101) genes in some families with hypodontia involving both second premolars and lateral incisors.
In a family segregating autosomal dominant oligodontia, Stockton et al. ... Nieminen et al. (1995) excluded involvement of the MSX1 (142983) and MSX2 (123101) genes in some families with hypodontia involving both second premolars and lateral incisors. In a family segregating autosomal dominant oligodontia, Stockton et al. (2000) identified heterozygosity for an insertion of a guanine at nucleotide 219 of the PAX9 gene (167416.0001) in affected individuals. Das et al. (2002) noted that mutations in the PAX9 gene had been found to cause both oligodontia (e.g., 167416.0002) and hypodontia (e.g., 167416.0003). They suggested that the disorders may not be fundamentally different. Frazier-Bowers et al. (2002) identified a novel insertion mutation in the PAX9 gene (167416.0010) in a large family with autosomal dominant oligodontia. Lammi et al. (2003) identified a novel missense mutation in the PAX9 gene (167416.0008) in affected members of a Finnish family segregating autosomal dominant oligodontia. Mostowska et al. (2006) detected a mutation in the PAX9 gene (167416.0012) in all affected individuals in a 3-generation family with severe autosomal dominant oligodontia. In affected members of a family segregating molar oligodontia, Kapadia et al. (2006) identified a heterozygous missense mutation in the PAX9 gene (167416.0009). Based on functional studies of the mutant and wildtype proteins, Kapadia et al. (2006) suggested that the pathogenesis of oligodontia in this family involves a loss-of-function mechanism that contributes to haploinsufficiency of PAX9.