We propose to conduct a population-based case-control study of facial clefts (cleft lip or palate) in Norwegian newborns. Cleft lip and palate are one of the most common type of birth defect, and both genetic and environmental causes have been suspected. This project will combine tests of recently-discovered genes associated with facial clefting and personal interviews of the mothers soon after birth. With this information we expect to be able to assess the combined role of genetic susceptibility and environmental exposures in causation of facial clefts. We plan to enroll 750 cases and 1100 controls over five years. This will provide a 2:1 ratio of controls to cases for the largest sub-category of facial clefts (cleft lip with or without cleft palate).

This study is being conducted as a collaboration between the US National Institute of Environmental Health Sciences, and the Norwegian Institute of Public Health/Medical Birth Registry. Norway offers a unique opportunity for carrying out such a study. First, all Norwegian babies with facial clefts are treated at one of two medical centers at the expense of the national government. Our collaboration with these two clinics will provide access to virtually every case born in the country. Second, the Medical Birth Registry maintains a file of all newborn babies, from which control infants can be randomly drawn from the whole population. Random population controls are the gold standard for such studies, but are seldom feasible. Third, blood samples from all Norwegian newborns are sent to one laboratory for analysis of PKU. Our collaboration with the PKU laboratory will permit mothers of control infants to consent to the study of their baby's blood without having to submit their baby to an additional needle stick.

Mothers of cases and controls will be initially contacted through their physicians, and will be asked to participate in a telephone interview. With their consent, the mothers will also be asked to provide biological samples for analysis of genes that predispose to facial clefts. We will collect cheek swabs from control mothers and their infants. Case mothers will be asked to provide additional blood samples and cheek swabs for more intensive study of genetic factors within their family. Protection of privacy will be paramount. Mothers of case infants will be given the option of receiving individual results, but only if a consulting panel of ethicists and other experts agree that such information will be beneficial.

Analysis and presentation of data will be carried out jointly by US and Norwegian investigators.

We propose to conduct a population-based case-control study of facial clefts (cleft lip or palate) in Norwegian newborns. Cleft lip and palate are one of the most common type of birth defect, and both genetic and environmental causes have been suspected. This project will combine tests of recently-discovered genes associated with facial clefting and personal interviews of the mothers soon after birth. With this information we expect to be able to assess the combined role of genetic susceptibility and environmental exposures in causation of facial clefts. We plan to enroll 750 cases and 1100 controls over five years. This will provide a 2:1 ratio of controls to cases for the largest sub-category of facial clefts (cleft lip with or without cleft palate).

This study is being conducted as a collaboration between the US National Institute of Environmental Health Sciences, and the Norwegian Institute of Public Health/Medical Birth Registry. Norway offers a unique opportunity for carrying out such a study. First, all Norwegian babies with facial clefts are treated at one of two medical centers at the expense of the national government. Our collaboration with these two clinics will provide access to virtually every case born in the country. Second, the Medical Birth Registry maintains a file of all newborn babies, from which control infants can be randomly drawn from the whole population. Random population controls are the gold standard for such studies, but are seldom feasible. Third, blood samples from all Norwegian newborns are sent to one laboratory for analysis of PKU. Our collaboration with the PKU laboratory will permit mothers of control infants to consent to the study of their baby's blood without having to submit their baby to an additional needle stick.

Mothers of cases and controls will be initially contacted through their physicians, and will be asked to participate in a telephone interview. With their consent, the mothers will also be asked to provide biological samples for analysis of genes that predispose to facial clefts. We will collect cheek swabs from control mothers and their infants. Case mothers will be asked to provide additional blood samples and cheek swabs for more intensive study of genetic factors within their family. Protection of privacy will be paramount. Mothers of case infants will be given the option of receiving individual results, but only if a consulting panel of ethicists and other experts agree that such information will be beneficial.

Analysis and presentation of data will be carried out jointly by US and Norwegian investigators.

• INCLUSION CRITERIA:

We expect to be able to recruit the mothers of virtually all Norwegian babies born with facial clefts during the study period (1995-1999).

Controls will be chosen randomly from all Norwegian live-births through the Medical Birth Registry.

EXCLUSION CRITERIA:

There will be no exclusion by race, sex or ethnic group.