Tricho-Dento-Osseous Syndrome

Resident’s Name: Joanne Lewis Date: February 5, 2010

Article title: Analysis of the Tricho-Dento-Osseous Syndrome Genotype and Phenotype

Author(s): Wright, J. Tim DDS MS, et al

Journal: American Journal of Medical Genetics

Volume (number): 72

Date: 1997

Major topic: Tricho-Dento-Osseous Syndrome

Type of Article: scientific article

Main Purpose: to characterize the phenotype of TDO in 3 previously undescribed kindreds in North Carolina and to test genetic linkage to specific candidate regions.

Overview of method of research: 53 individuals (33 affected individuals and 20 non-affected individuals) were recruited to participate in the study. Detailed family histories as well as medical and dental histories were obtained for each individual. Participants were evaluated clinically and radiographically. Blood was drawn for genetic linkage analysis.

Findings: Curly/kinky hair at birth was found in 85% of affected individuals, with 46% retaining the curly hair phenotype after infancy. The TDO teeth were small (due to enamel hypoplasia) and often had a slight yellow-brown coloration. Pitting and/or furrowing of the enamel was evident in 63% of the teeth. Dental abscesses were reported by 77% of individuals with TDO, as opposed to 25% of unaffected persons. Taurodontism was present in some degree in all affected individuals. Skeletal manifestations in TDO varied substantially and included an increase in cranial bone density, calvarial diploe obliteration, and a lack of visible mastoid pneumatization.

Key points/Summary: Curly hair at birth, enamel hypoplasia, and taurodontism are highly penetrant yet clinically variable components of TDO. The ABO, Kell, and Gc loci previously suggested to be linked to TDO were excluded as candidates in this TDO population.

Assessment of article: Provides support for the “soft-tooth” theory.