OBJECTIVE: To assess the predictive value of fetal nuchal translucency (NT) measurement in the prenatal diagnosis of single-gene disorders. METHODS: From January 1996 to December 2006, fetal NT was prospectively measured before chorionic villi sampling in 169 pregnancies at high risk for a single-gene disorder at 11 to 13 weeks of pregnancy. RESULTS: No differences were found between the 63 affected and 116 nonaffected fetuses in pregnancy demographic characteristics, in mean NT measurements, expressed either in millimetres [1.8 (95% CI:1.6-1.9) vs 1.7 (95% CI:1.6-1.8)] or in multiples of the median [1.19 (95%CI: 1.04-1.35) vs 1.14 (95%CI: 1.05-1.23)], or in median NT. The percentage of increased NT above the 95(th) percentile was similar for affected (9.5%) and nonaffected (11.2%) fetuses. CONCLUSION: Not all single-gene disorders are associated with enlarged NT, therefore NT cannot be regarded as a generic marker for single-gene disorder but only for a limited number of these conditions.
OBJECTIVE: To assess the predictive value of fetal nuchal translucency (NT) measurement in the prenatal diagnosis of single-gene disorders. METHODS: From January 1996 to December 2006, fetal NT was prospectively measured before chorionic villi sampling in 169 pregnancies at high risk for a single-gene disorder at 11 to 13 weeks of pregnancy. RESULTS: No differences were found between the 63 affected and 116 nonaffected fetuses in pregnancy demographic characteristics, in mean NT measurements, expressed either in millimetres [1.8 (95% CI:1.6-1.9) vs 1.7 (95% CI:1.6-1.8)] or in multiples of the median [1.19 (95%CI: 1.04-1.35) vs 1.14 (95%CI: 1.05-1.23)], or in median NT. The percentage of increased NT above the 95(th) percentile was similar for affected (9.5%) and nonaffected (11.2%) fetuses. CONCLUSION: Not all single-gene disorders are associated with enlarged NT, therefore NT cannot be regarded as a generic marker for single-gene disorder but only for a limited number of these conditions.