Iniencephaly and chromosome mosaicism: a report of two cases.

We report here two iniencephaly fetuses with chromosome mosaicism. The first fetus (22 weeks) was male with mosaic trisomy 13, and the second fetus (24 weeks) was female with mosaic monosomy X. The first fetus had anencephaly, facial clefting, left-sided rocker bottom foot, equinovarous deformity, bilateral simian crease of hands and horseshoe kidney in addition to iniencephaly. The second fetus had hydrops fetalis with cystic hygroma in addition to iniencephaly. Because the fetuses were sent in formalin, conventional chromosomal analysis was not possible in spite of strong indication. Interphase fluorescence in situ hybridization (FISH) was carried out for targeted aneuploidy analysis. This is fourth published report of chromosomal abnormality in iniencephaly.