Homozygous alpha-thalassemia with trisomy 7 mosaicism in a live-born infant.

The authors report a male infant born at 35 weeks gestational age with an atypical presentation of homozygous alpha-thalassemia. The live-born infant displayed abnormalities of the upper limbs and genitalia, which are vascular-type disruptive defects associated with this disease. Cardiomegaly and placentomegaly were the only evidence of fetal hydrops. Postnatal karyotype revealed mosaicism for trisomy 7, yet another rare finding in a live-born. The authors discuss their institutional experience with each of these rare conditions and the potential contribution of each to the overall unusual clinical presentation in this patient. This is the first report of these simultaneous diagnoses.