Craniometaphyseal dysplasia--variability of expression within a large family

Fifteen individuals in five generations of a kindred with branches in South Africa and England had the autosomal dominant form of craniometaphyseal dysplasia. The majority of affected adults had mild to moderate mandibular distortion, while paranasal bossing was a transient manifestation in childhood. Facial palsy with onset in childhood was present either unilaterally or bilaterally in about 30% of the patients, while 50% had auditory dysfunction which varied from mild impairment of hearing to total deafness. Stature and intellect were normal, and bone fragility, osteomyelitis and dyshaemopoesis were not features of the condition. Five other potentially affected family members had deafness or facial palsy of uncertain aetiology in the absence of other stigmata of CMD. It is uncertain whether these complications represent minor degrees of phenotypic expression of the abnormal gene.