Amniotic band syndrome: the association between rare facial clefts and limb ring constrictions.

The pathologic cause of both rare craniofacial clefts and congenital limb ring constrictions is the subject of some debate. Uncommon though these two conditions are, they have often been anecdotally reported in association. This study sought to determine the frequency of congenital limb anomalies in general and limb ring constrictions in particular amongst a population of patients with rare craniofacial clefts. Eighty-five cases of nonsyndromal, rare, craniofacial cleft were identified from a population of 280 patients assessed at the Women's and Children's Hospital, North Adelaide, with a diagnosis of rare craniofacial cleft classifiable by the Tessier system. Twenty-two patients (25.9 percent) displayed congenital limb anomalies. Eleven of these (12.9 percent) showed evidence of limb ring constrictions, a frequency much greater than in the general population. The group with limb ring constrictions demonstrated a significantly greater complexity of involvement with craniofacial clefting than the non-limb ring constriction group (4.27 clefts/patient versus 2.3 clefts/patient, p < 0.01). The distribution of craniofacial cleft locations in patients with evidence of limb ring constrictions was found to differ significantly from those with other or no limb anomalies (p < 0.01). The clefts in cases in which limb ring constrictions coexist are largely restricted to the paramedian 2-12, 3-11, 412 axes. This study confirms an association between rare craniofacial clefts and limb ring constrictions. The two conditions may therefore possess common etiology.