Hemifacial microsomia: from gestation to childhood.

Hemifacial microsomia (HFM) is a variable, complex malformation involving asymmetric hypoplasia of the face and ear. Little is known about the risk factors for or consequences of HFM. In this study, we describe 3 studies that have been or are currently being conducted to further our understanding of this malformation. The first completed study examined whether HFM risk is related to maternal exposures that may affect blood flow. In that case-control study, interview data from 230 mothers of children in the case group and 678 mothers of children in the control group suggested that maternal use of vasoactive medications in the first trimester, particularly in combination with cigarette smoking, was associated with increased risks of HFM. The second study is currently underway, in which we are evaluating whether HFM risk is related to genetic variation in pathways associated with vasculogenesis and hemostasis, using DNA collected in the first study. The third ongoing study observes children with HFM to identify psychosocial, cognitive, dental, and medical sequelae. When the children from the original case-control study are 6 or 7 years of age, mothers and teachers complete self-administered questionnaires that cover a wide range of psychosocial development domains. Preliminary analyses of 115 case and 314 control children suggest that children with HFM may have worse teacher-reported academic performance and possibly higher levels of internalizing behavior problems than control children. When data on the full study sample are available, further analyses will determine whether the preliminary findings remain and if they vary by HFM phenotype, parenting style, or indicators of social risk.