Identification of a nonsense mutation in the amelogenin gene (AMELX) in a family with X-linked amelogenesis imperfecta (AIH1)

A family with X-linked amelogenesis imperfecta (XAI) is described in which the disease is associated with a nonsense mutation in exon 5 of the amelogenin gene. This mutation involves a single base deletion (CCCC-->CCC) in the exon in an affected male, his sister and his mother. The effect of this deletion is to alter the reading frame and to introduce an inappropriate TGA stop codon (an opal mutation) into the exonic sequence of the amelogenin gene immediately 3' of the mutation. The clinical features in the examined members of this family indicate that, in some individuals, the most noticeable defect is of enamel hypoplasia. In others, the hypoplastic changes are subtle and might have been overlooked on cursory examination; the most noticeable change is of enamel colour, indicating a degree of hypomineralisation. We propose that the amelogenin gene is implicated in both the formation of enamel of normal thickness and in the normal mineralisation process.

Genetic heterogeneity in X-linked amelogenesis imperfecta

The AMELX gene located at Xp22.1-p22.3 encodes for the enamel protein amelogenin and has been implicated as the gene responsible for the inherited dental abnormality X-linked amelogenesis imperfecta (XAI). Three families with XAI have been investigated using polymorphic DNA markers flanking the position of AMELX. Using two-point linkage analysis, linkage was established between XAI and several of these markers in two families, with a combined lod score of 6.05 for DXS16 at theta = 0.04. This supports the involvement of AMELX, located close to DXS16, in the XAI disease process (AIH1) in those families. Using multipoint linkage analysis, the combined maximum lod score for these two families was 7.30 for a location of AIH1 at 2 cM distal to DXS16. The support interval around this location extended about 8 cM proximal to DXS92, and the AIH1 location could not be precisely defined by multipoint mapping. Study of recombination events indicated that AIH1 lies in the interval between DXS143 and DXS85. There was significant evidence against linkage to this region in the third family, indicating locus heterogeneity in XAI. Further analysis with markers on the long arm of the X chromosome showed evidence of linkage to DXS144E and F9 with no recombination with either of these markers. Two-point analysis gave a peak lod score at DXS144E with a maximum lod score of 2.83 at theta = 0, with a peak lod score in multipoint linkage analysis of 2.84 at theta = 0. The support interval extended 9 cM proximal to DXS144E and 14 cM distal to F9.(ABSTRACT TRUNCATED AT 250 WORDS)

Salivary IgA antigliadin antibody as a marker for coeliac disease

In recent years, serum antibodies to gliadin (AGA) have been reported to be useful markers of coeliac disease. IgA AGA have also been found in intestinal secretions and saliva in coeliac disease and may offer a convenient, non-invasive screening test. In order to test this hypothesis, salivary and serum AGA were measured in children with coeliac disease proved by biopsy and compared with several control groups. Measurement of salivary IgA AGA provided excellent discrimination between those children with coeliac disease and the control groups, and our study suggests that it may provide a rapid, non-invasive method of screening for this disease before intestinal biopsy.

Unusual dentinal changes in dentinogenesis imperfecta associated with osteogenesis imperfecta. A case report

A case is described of a boy with dentinogenesis imperfecta associated with osteogenesis imperfecta. The dentin of extracted deciduous teeth was found to show an abrupt transition to a normal tubular structure before a reversion to the more typical structure seen in dentinogenesis imperfecta. This change in the dentin appeared to have occurred in a chronologic manner. The possibilities that either a metabolic disturbance or a temporary reduced expression of the mutant gene had caused the abnormality and could account for the unusual histologic findings are discussed.

An unusual giant cell lesion in a child with vitamin D-resistant rickets

This paper reports the presence of a focus of giant cells in a sinus tract associated with an abscessed primary tooth in a patient with vitamin D-resistant rickets. The relevance of this giant cell lesion to the systemic disorder is discussed.

X-linked amelogenesis imperfecta. Presentation of two kindreds and a review of the literature

Two families with X-linked amelogenesis imperfecta are described. A critical review of previously reported cases of this condition is presented.

Scanning electron microscopic study of primary teeth in X-linked amelogenesis imperfecta

Exfoliated primary teeth from a boy and a girl from a family with X-linked amelogenesis imperfecta (XAI) were studied by scanning electron microscopy. Teeth from the boy featured multiple shallow depressions on the enamel surface interspersed with deeper tubular voids. Shallow depressions and similar tubular defects were also apparent in control teeth from an unaffected individual but these were less frequent, irregularly distributed and less marked. Teeth from the heterozygous girl had broad furrows running longitudinally from the cusp(s) of the tooth cervically. These furrows were formed by a series of saucerized depressions which merged together in some areas. The bases of these depressions featured tubular voids extending into the enamel. These similar voids in teeth from both boy and girl probably represent enamel prism spaces vacant because of defective enamel protein synthesis and/or mineralization. Although the scanning electron microscopic features of teeth from females observed in this and previous studies of XAI differ, the enamel appears to be more similar in males with differing clinical XAI phenotypes.

Oral health in the terminally ill: a cross-sectional pilot survey

This study of 20 hospice patients provided baseline information on oral and dental status in the terminally ill. For each patient, a questionnaire was completed, the mouth was examined, and an oral rinse and imprint cultures were collected to establish the prevalence and intra-oral density of yeasts, staphylococci and coliforms. Oral symptoms reported included disturbance of taste (26%), dysphagia (37%), soreness (42%), and dryness (58%). Of the 75% who wore dentures, 71% had difficulty with their prosthesis (es). A clinical diagnosis of oral candidiasis was made in 70% of subjects. The high prevalence of oral symptoms, denture problems, and candidiasis clearly affect the quality of remaining life in terminally ill patients.

Clinical and radiographic dental findings in X linked hypohidrotic ectodermal dysplasia

X linked hypohidrotic ectodermal dysplasia was studied in the dentition of both affected males and carrier females. Hypodontia was more severe in males than females and there were differences in the pattern of tooth absence between the sexes. Abnormal crown form, with the maximum diameter of the teeth being apically displaced, was noted particularly in the anterior teeth. Taurodontism was commonly seen radiographically.

Comparison of identification methods for oral asaccharolytic Eubacterium species

Thirty one strains of oral, asaccharolytic Eubacterium spp. and the type strains of E. brachy, E. nodatum and E. timidum were subjected to three identification techniques--protein-profile analysis, determination of metabolic end-products, and the API ATB32A identification kit. Five clusters were obtained from numerical analysis of protein profiles and excellent correlations were seen with the other two methods. Protein profiles alone allowed unequivocal identification.

Amelogenesis imperfecta with taurodontism and the tricho-dento-osseous syndrome: separate conditions or a spectrum of disease?

Various authors have allocated a diagnosis of tricho-dento-osseous syndrome to cases originally reported as amelogenesis imperfecta (hypomaturation-hypoplasia type) with taurodontism. The resulting confusion has prompted this critical review of the literature, and further information has been obtained from the authors concerned. Criteria for diagnosis of the two conditions are proposed.

A pigmented adenomatoid odontogenic tumor

Occasional reports have described the presence of melanin in various odontogenic lesions. A case of melanin pigmentation in an adenomatoid odontogenic tumor is described.

Protein profiles of Capnocytophaga species

Ninety-seven strains of Capnocytophaga isolated from the oral cavity and the type strains of C. ochracea, C. sputigena and C. gingivalis were compared by one-dimensional SDS-PAGE of whole cell proteins. The protein patterns were highly reproducible and were used as the basis for numerical taxonomic analysis. The clusters containing the type strains of C. ochracea and C. sputigena segregated at the 78% similarity level. Some of the eight clusters obtained at this level showed good correlation with grouping based on the results of biochemical testing for lactose and galactose fermentation and nitrate reduction. No consistent association was found between protein profiles and colony type, size or colour or cell length but all agar-adherent colony types segregated into a single cluster.

A rapid, semi-automated SDS-PAGE identification system for oral anaerobic bacteria

SDS-polyacrylamide gel electrophoresis is a useful technique in bacterial differentiation and identification. A rapid, semi-automated SDS-PAGE system (Phast System) was assessed for identification of formate-fumarate-requiring, asaccharolytic, Gram-negative oral anaerobes. The system permitted loading, separation and staining of gels within 2 h. Percentage similarities between strains were determined using correlation coefficients and cluster analysis. The protein profiles were sufficiently reproducible provided that distorted profiles were disregarded. Strains were successfully separated into their species, with the exception of Bacteroides ureolyticus NCTC 10939, which appeared to be distinct from other strains of that species. Twenty-nine unidentified formate-fumarate-requiring, sub-gingival plaque strains were suitably clustered with the standard strains as verified by a series of physiological and biochemical tests.

Colour teaching aids in oral pathology

A simple and cost effective photographic method is described for presenting case materials to assist in the practical teaching of Oral Medicine and Pathology to undergraduate dental students. The information contained in each presentation is comprised of clinical radiographic and histopathological material.

Salivary and serum antibodies to gliadin in the diagnosis of celiac disease

Salivary IgA and serum IgA and IgG antibodies to crude gliadin and alpha-gliadin were measured in adult patients with untreated celiac disease, ulcerative colitis, Crohn's disease and normal controls. Antibody levels in saliva and serum in untreated celiac disease were significantly higher than in other groups. Alpha-gliadin antibodies appeared to be a better discriminator for serum but not for saliva. The assay of salivary IgA antibodies to gliadin offers a non-invasive test which would be particularly useful in the investigation of celiac disease and for monitoring compliance with a gluten-free diet.

Massive giant cell epulis in a child with familial cyclic neutropenia

A case of a boy with familial cyclic neutropenia and a large giant cell epulis is reported. The clinical management is described and the significance of the neutropenia in relation to subsequent infection of the epulis is discussed.

Non-osteogenic fibroma of the mandibular condyle

Non-osteogenic fibroma is a lesion most commonly seen within the metaphyseal region of the tibia or femur presenting during the second decade. Few cases have been reported in the jaws and all occurred in the mandible. This report documents an 18-year-old female with a non-osteogenic fibroma in the condyle.

Frequency and density of yeasts in the mouths of malnourished children

The prevalence and density of yeasts and Candida albicans on the buccal mucosa and dorsum of the tongue have been assessed in 106 children in Crossroads squatter camp, South Africa. They were divided into a malnourished and a control group on the basis of an age/weight chart. No differences were found in yeast prevalence and density in the two groups. However, malnourished children more frequently had a mucosal density of yeasts, and particularly C. albicans, exceeding the upper limit normally found in health, in the absence of clinical infection. Some evidence was found to suggest that yeast density might be influenced by sex as well as nutritional status.

Regional odontodysplasia: a bibliography

Regional odontodysplasia is a localized disorder of tissues of dental origin resulting in characteristically bizarre clinical and radiographic appearances. It most commonly affects the maxillary anterior teeth of both the permanent and primary dentitions. The authors present a worldwide bibliography of reported cases and discuss the suggested theories regarding the condition's etiology. Although the majority of cases of regional odontodysplasia must be regarded as idiopathic, various developmental anomalies may produce identical changes in the teeth in one or more quadrants. A number of previously reported cases are also reconsidered with regard to their diagnosis and guidelines are suggested for the treatment of patients affected by regional odontodysplasia.

Paget's disease of bone with involvement of the dental pulp

A case of Paget's disease of bone in a 65-yr-old woman is described with partial obliteration of the pulps of teeth in the affected mandible. This hard tissue had the typical mosaic pattern of bone or cementum seen in that condition.

Rapp-Hodgkin syndrome: an ectodermal dysplasia involving the teeth, hair, nails, and palate. Report of a case and review of the literature

Rapp-Hodgkin syndrome is a rare form of ectodermal dysplasia involving the hair, eyes, sweat glands, nails, teeth, and palate. The case of a white girl with the condition is presented. The differential diagnosis is discussed, and the eight previously reported cases are reviewed. Another (ninth) previously reported case is considered for inclusion in the group.

Variable expression in Amelogenesis imperfecta with taurodontism

The hypomaturation-hypoplasia type of Amelogenesis imperfecta with taurodontism is a rare condition. All previously documented cases have featured clinically involved teeth in successive generations. A family is presented in which the son was affected clinically and radiographically, whereas the teeth of his sister and mother were clinically normal but radiographically had the taurodont morphology. Molars extracted from the boy showed both hypoplasia and hypomineralisation on histopathological examination. It is proposed that the taurodont tooth form in the sister and mother represents a partial manifestation of the condition.