We present an epidemiologic study of the cases of cleft lip and cleft
palate in Mississippi from 1980 through 1989. Cases were stratified by
race (white and nonwhite) but not by association with a major malform
ation. During this period, a total of 457 new patients with cleft lip
or cleft palate were identified from a population of approximately 439
,354 live births. The incidence of total clefts in live-born infants w
as 1.36/1,000 for whites and 0.54/1,000 for nonwhites. White boys had
a higher incidence of cleft lip and palate than white girls; black boy
s had an extremely low incidence of cleft lip, whereas black girls sho
wed a higher incidence of cleft palate alone. Examination of the rate
of cleft malformations for each county in Mississippi revealed no clea
rly defined pattern, nor were we able to demonstrate that rates were i
ncreased in a major agricultural area of the state, in which use of po
tentially toxic products is high.