Connexin 43 (GJA1) mutations cause the pleiotropic phenotype of oculodentodigital dysplasia. (1/13)

Gap junctions are assemblies of intercellular channels that regulate a variety of physiologic and developmental processes through the exchange of small ions and signaling molecules. These channels consist of connexin family proteins that allow for diversity of channel composition and conductance properties. The human connexin 43 gene, or GJA1, is located at human chromosome 6q22-q23 within the candidate region for the oculodentodigital dysplasia locus. This autosomal dominant syndrome presents with craniofacial (ocular, nasal, and dental) and limb dysmorphisms, spastic paraplegia, and neurodegeneration. Syndactyly type III and conductive deafness can occur in some cases, and cardiac abnormalities are observed in rare instances. We found mutations in the GJA1 gene in all 17 families with oculodentodigital dysplasia that we screened. Sixteen different missense mutations and one codon duplication were detected. These mutations may cause misassembly of channels or alter channel conduction properties. Expression patterns and phenotypic features of gja1 animal mutants, reported elsewhere, are compatible with the pleiotropic clinical presentation of oculodentodigital dysplasia.  (+info)

Rabson-Mendenhall syndrome. (2/13)

Rabson-Mendenhall syndrome is characterized by growth retardation, dysmorphisms, lack of subcutaneous fat, acanthosis nigricans, enlarged genitalia, hirsutism, premature and dysplastic dentition, coarse facial features, paradoxical fasting hypoglycemia and post-prandial hyperglycemia, extreme hyperinsulinemia and pineal hyperplasia. We describe a six-month-old female child with physical features suggestive of the Rabson-Mendenhall syndrome. The child also had medullary nephrocalcinosis.  (+info)

Conservative management of regional odontodysplasia: case report. (3/13)

Regional odontodysplasia is an uncommon developmental anomaly affecting a localized area of the dentition. The affected teeth are often grossly malformed and develop abscess soon after eruption. Although extractions are often required, in some milder cases the teeth may be retained for a long period. The treatment plan should be based on the degree of involvement as well as functional and esthetic needs in each case. This article describes a conservative treatment approach in a 10-year-old boy with regional odontodysplasia.  (+info)

Mutation in WNT10A is associated with an autosomal recessive ectodermal dysplasia: the odonto-onycho-dermal dysplasia. (4/13)

Odonto-onycho-dermal dysplasia is a rare autosomal recessive syndrome in which the presenting phenotype is dry hair, severe hypodontia, smooth tongue with marked reduction of fungiform and filiform papillae, onychodysplasia, keratoderma and hyperhidrosis of palms and soles, and hyperkeratosis of the skin. We studied three consanguineous Lebanese Muslim Shiite families that included six individuals affected with odonto-onycho-dermal dysplasia. Using a homozygosity-mapping strategy, we assigned the disease locus to an ~9-cM region at chromosome 2q35-q36.2, located between markers rs16853834 and D2S353, with a maximum multipoint LOD score of 5.7. Screening of candidate genes in this region led us to identify the same c.697G-->T (p.Glu233X) homozygous nonsense mutation in exon 3 of the WNT10A gene in all patients. At the protein level, the mutation is predicted to result in a premature truncated protein of 232 aa instead of 417 aa. This is the first report to our knowledge of a human phenotype resulting from a mutation in WNT10A, and it is the first demonstration of an ectodermal dysplasia caused by an altered WNT signaling pathway, expanding the list of WNT-related diseases.  (+info)

Regional odontodysplasia of the deciduous and permanent teeth associated with eruption disorders: A case report. (5/13)

Regional odontodysplasia (RO) is an unusual, non-hereditary anomaly of the dental hard tissues with characteristic clinical, radiographic and histological findings. Clinically, RO affects the primary and permanent dentition in the maxilla and mandible or both jaws. Radiographically, there is a lack of contrast between the enamel dentin, both of which are less radiopaque than unaffected counterparts. Additionally, enamel and dentin layers are thin, giving the teeth a "ghost-like" appearance. Histologically, areas of hypocalcified enamel are visible and enamel prisms appear irregular in direction. Coronal dentin is fibrous, consisting of clefts and a reduced number of dentinal tubules; radicular dentin is generally more normal in structure and calcification. The RO etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation, hypophosphatasia, hypocalcemia, hyperpyrexia. The treatment of RO has given rise to controversy. These cases require a continuous and multidisciplinary approach. Most clinicians advocate extracting the affected teeth as soon as possible and inserting a prosthetic replacement. Other clinicians prefer restorative procedures, if possible, to protect the affected erupted teeth. A case of RO in an 8 year-old male whose chief complaint was the absence of eruption of permanent teeth is presented. Clinical, radiographic and histological findings are described.  (+info)

Regional odontodysplasia in early childhood: a clinical and histological study. (6/13)

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Dental management of oculodentodigital dysplasia: a case report. (7/13)

Oculodentodigital dysplasia is an extremely rare autosomal dominant pleiotropic disorder. The syndrome is characterized by abnormal facial features, central nervous system involvement, syndactyly and clinodactyly of fourth and fifth fingers, dry and lusterless hair, generalized enamel hypoplasia and odontodysplasia. Combination of odontodysplasia, poor oral hygiene, and parental neglect can lead to extensive destruction of tooth structure and the treatment options become limited. Early diagnosis with a proper treatment plan and meticulous oral hygiene program helps eliminate the necessity of multiple tooth extractions. This case report describes the comprehensive dental treatment aimed at rehabilitation of function and aesthetics of the dentition in an 8-year-old boy with oculodentodigital dysplasia.  (+info)

Regional odontodysplasia. (8/13)

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