CASE-REPORT Low-level trisomy 14 mosaicism in a male newborn with ectrodactyly

Complete trisomy 14 mosaicism is a rare chromosome disorder and was first reported in 1970. We describe a case of a male neonate who presented complete trisomy 14 mosaicism in only 4% of the cells from peripheral blood. A nineteen-day-old male neonate was born as result of the second pregnancy. The infant was delivered by cesarean section due to gestational hypertension and chronic fetal distress. The length of the term pregnancy was 37 weeks, the birth weight was 3.105 g, the length was 48 cm, and the head circumference was 35.5 cm. The baby remained hospitalized for 19 days in the neonatal intensive care unit due to respiratory distress syndrome and congenital malformations. Physical examination revealed a toned and normal activity, followed by phenotypic changes such as a broader forehead, formation of a cleft palate, hypertelorism, low-set ears, bilateral cryptorchidism, absence of the second toe of the left foot (ectrodactyly), and fusion of third and fourth toes in the right foot (bilateral syndactyly). Cytogenetic analysis was performed on peripheral blood cultures after hospitalization in the neonatal intensive care unit. Analysis of 200 G-banded metaphases showed that 192 (96%) had normal karyotype 46,XY and only 8 (4%) presented trisomy 47,XY,+14. It was not possible to perform cytogenetic analysis on the patient's parents. Our patient represents the first case of trisomy 14 disorder to present ectrodactyly.