Oculo dento digital dysplasia

Oculo-Dento-Digital Dysplasia

Oculo-Dento-Digital Dysplasia (ODDD) is a rare genetic disorder characterized by a combination of ocular, dental, and digital abnormalities. It is an autosomal dominant condition, meaning that a single copy of the altered gene in each cell is sufficient to cause the disorder. The condition is caused by mutations in the GJA1 gene, which encodes the protein connexin 43, a component of gap junctions that facilitate cell-to-cell communication.

Clinical Features

ODDD presents with a variety of clinical features that can affect multiple systems:

Ocular Abnormalities

Individuals with ODDD may experience:

• Microphthalmia: Abnormally small eyes.
• Glaucoma: Increased intraocular pressure that can lead to vision loss.
• Cataracts: Clouding of the lens of the eye.
• Coloboma: A defect in the structure of the eye.

Dental Abnormalities

Dental issues are common in ODDD and may include:

• Enamel hypoplasia: Underdeveloped enamel leading to weak teeth.
• Microdontia: Abnormally small teeth.
• Anodontia: Missing teeth.
• Malocclusion: Misalignment of the teeth.

Digital Abnormalities

Digital anomalies are a hallmark of ODDD and can include:

• Syndactyly: Fusion of fingers or toes.
• Camptodactyly: Permanent bending of the fingers.
• Brachydactyly: Shortened fingers or toes.

Other Features

Additional features may include:

• Craniofacial dysmorphism: Distinctive facial features such as a long, thin nose and small chin.
• Neurological issues: Such as developmental delay or seizures.
• Skeletal abnormalities: Such as scoliosis or joint hypermobility.

Genetics

ODDD is caused by mutations in the GJA1 gene located on chromosome 6q22-q23. The GJA1 gene encodes connexin 43, a protein that forms gap junctions, which are essential for direct intercellular communication. Mutations in this gene disrupt the function of gap junctions, leading to the diverse clinical manifestations of the disorder.

Diagnosis

Diagnosis of ODDD is based on clinical evaluation, family history, and genetic testing to identify mutations in the GJA1 gene. Imaging studies, such as X-rays or MRIs, may be used to assess skeletal and craniofacial abnormalities.

Management

Management of ODDD is symptomatic and supportive. It may involve:

• Regular ophthalmologic evaluations to monitor and treat eye conditions.
• Dental care to address enamel defects and malocclusion.
• Orthopedic interventions for digital and skeletal abnormalities.
• Genetic counseling for affected individuals and their families.

Epidemiology

ODDD is a rare disorder with an estimated prevalence of less than 1 in 100,000 individuals. It affects males and females equally and has been reported in various ethnic groups.

Also see

• Genetic disorders
• Connexin proteins
• Autosomal dominant inheritance
• Syndactyly

NIH genetic and rare disease info

• NIH info on Oculo dento digital dysplasia

Oculo dento digital dysplasia is a rare disease.