BACKGROUND: Hereditary neuralgic amyotrophy (HNA) is an autosomal-dominant disorder associated with recurrent, episodic, painful, brachial neuropathy. The gene for HNA has been mapped to chromosome 17q25. Characteristic features including hypotelorism, short stature, and cleft palate occur in some patients. OBJECTIVE: To further characterize the clinical, neurologic, and craniofacial features in 27 patients from seven families with HNA. METHODS: Medical history, physical examination, and facial measurements were obtained. Facial measurements were also made on 60 healthy controls. RESULTS: Twenty-five patients had an average of three attacks of brachial neuritis. The right arm was involved more frequently. Cleft palate was present in four individuals. Facial measurements showed significant hypotelorism in HNA patients versus controls. Unusual skin folds and creases were observed on the necks of several individuals as well as on the scalp of one man: cutis verticis gyrata. In three families, deep skin creases were present on the limbs of infants and toddlers who were subsequently affected with HNA. CONCLUSIONS: The phenotypic consequences of the mutant hereditary neuralgic atrophy gene may include a wider spectrum than previously appreciated and involve nonneural tissue.