Prenatal sonographic features of trisomy 1q

We describe the sonographic features of trisomy 1q in 2 affected fetuses and identify 17 other published reports of this entity in the literature. Four of 5 (80%) diagnoses made at < or = 14 weeks' gestation demonstrated increased nuchal translucency or cystic hygroma colli. During the second and third trimesters, findings included cerebral ventriculomegaly (n = 8 [57%]), nuchal skin fold > or = 6 mm or cystic hygroma colli (n = 5 [36%]), urinary anomalies (n = 5 [36%]), digit malformations (n = 5 [36%]), and abnormal amniotic fluid volume (n = 6 [40%]). Findings in trisomy 1q may be influenced by coexisting chromosomal deletions or mosaicism. Sonographic features generally reflect the location and size of the 1q duplication.