Craniosynostosis. II. Coronal synostosis: its familial characteristics and associated clinical findings in 109 patients lacking bilateral polysyndactyly or syndactyly.

This paper is the second part of a survey of 370 patients with Craniosynostosis. It concerns 109 patients with coronal synostosis, with or without additional suture involvement who lacked polysyndactyly or syndactyly. Bilateral and unilateral coronal synostosis occurred with approximately equal frequency and there was an excess of males in both groups. Multiple suture involvements was frequent in patients with bilateral synostosis, but was uncommon in those with unilateral involvement. Those patients with bilateral synostosis and additional suture involvement were treated later than those with isolated bilateral synostosis and a possible explanation for this finding is discussed. Forty-seven percent of patients with bilateral synostosis had additional major malformations. Cardiac malformations were significantly more frequent than would be 'expected by chance. Thirty-five percent of patients with unilateral involvement had major malformations. Twenty-six percent of those with bilateral and ten percent of those with unilateral synostosis were mentally retarded, but retardation was found to be associated either with increased frequency of major malformations or with a complex medical history. Mental retardation is uncommon in simple, uncomplicated coronal synostosis. Twelye of the 104 families showed a positive family history; nine with vertical and three with horizontal transmission. An admixture of unilateral and bilateral suture involvement was the rule, and families with involvement limited to unilateral synostosis did not occur. Certain patterns of characteristic familial minor malformation, particularly of the hands, allow recognition of a number of these familial cases. The recurrence risks for coronal synostosis are discussed.