Prenatal diagnosis of the Meckel syndrome: use of serial ultrasound and alpha-fetoprotein measurements

The Meckel syndrome is a well known but somewhat variable malformation syndrome due to homozygosity for an autosomal recessive gene. Affected infants are often microcephalic and frequently have an occipital encephalocele. hypotelorism, eye abnormalities, cleft lip and/or palate, abnormal genitalia, polycystic kidneys, and postaxial polydactyly are also prominent features. The defect is lethal in utero or shortly after birth. Recent developments in the prenatal diagnosis of open neural tube defects suggest that the in utero diagnosis of the Meckel syndrome should be possible, and in fact this has been achieved in 2 cases in which a pregnancy known to be at risk for the Meckel syndrome was investigated with amniotic fluid alpha fetoprotein (AFP) determinations. The case being described in this communication is of particular interest because the diagnosis of the Meckel syndrome was not anticipated and because the serial use of amniotic fluid AFP determinations and of ultrasound measurements were utilized in arriving at a clinical decision to terminate an abnormal pregnancy.