Witkop Syndrome
Witkop Syndrome (Tooth and Nail Syndrome)
Witkop syndrome, also known as tooth and nail syndrome, is a rare autosomal dominant ectodermal dysplasia characterized by hypodontia and nail dysplasia. First described by Carl Witkop Jr. in 1965, it represents one of the mildest forms of ectodermal dysplasia.
Key Points
- Prevalence: Estimated at 1-9/100,000
- Inheritance: Autosomal dominant
- Gene: MSX1 mutations on chromosome 4p16.1
- Age of Onset: Early childhood
Clinical Manifestations
Dental Abnormalities
- Hypodontia (missing teeth) - primary feature
- Most commonly affected teeth:
- Second molars
- Upper lateral incisors
- Premolars
- Conical or peg-shaped teeth when present
- Normal enamel structure in existing teeth
Nail Dysplasia
- Toenails more severely affected than fingernails
- Characteristics:
- Spoon-shaped (koilonychia)
- Thin and soft
- Slow-growing
- Frequent onycholysis
- Progressive worsening with age
Associated Features
- Normal hair growth and structure
- Normal sweat glands function
- Regular facial features
- Normal intelligence and development
Genetic Basis & Inheritance
Molecular Genetics
- Caused by mutations in MSX1 gene
- Location: Chromosome 4p16.1
- Function: Transcription factor essential for:
- Tooth development
- Nail formation
- Craniofacial development
- 100% penetrance
- Variable expressivity
Inheritance Pattern
- Autosomal dominant transmission
- 50% risk of transmission to offspring
- High proportion of de novo mutations
Diagnosis & Management
Diagnostic Criteria
- Clinical Features:
- Hypodontia
- Nail dysplasia
- Family history (when present)
- Genetic Testing:
- MSX1 gene sequencing
- Deletion/duplication analysis
Management Approach
- Dental Care:
- Early orthodontic evaluation
- Dental prostheses
- Regular dental monitoring
- Implant consideration in adulthood
- Nail Care:
- Regular nail maintenance
- Prevention of secondary infections
- Protective footwear
- Genetic Counseling:
- Family planning
- Risk assessment
- Psychological support
