Recurrent enlarged nuchal translucency: first trimester presentation of a familial 15q26→qter deletion.

A 15q26 terminal chromosomal microdeletion was associated with markedly enlarged 1st trimester nuchal translucency in three of four pregnancies of a couple seen in our prenatal diagnosis unit. Nuchal translucency was normal in the couple's fourth pregnancy, which did not carry the microdeletion. The diagnosis of a 15q26.2→qter microdeletion was first made when the couple's affected daughter displayed significant postnatal growth delay and minor malformations consistent with this contiguous gene syndrome. The microdeletion was confirmed on archived material from the first pregnancy, and identified prospectively on chorionic villi in the third pregnancy. This is the second reported case of familial recurrence of this microdeletion syndrome. As in the other reported family, no deletion or chromosomal rearrangement was identified in either parent, suggesting gonadal mosaicism as a possible cause. First trimester ultrasound findings in 15q26 terminal deletion syndrome have not previously been described. This family illustrates the utility of performing prenatal chromosomal microarray testing in the presence of ultrasound findings of enlarged nuchal translucency or structural abnormalities.