Tetraploidy is an extremely rare chromosomal anomaly, polyploidy, when an affected individual has four copies of each chromosome, instead of two, resulting in total of 92 chromosomes in each cell. The phenotype is severe with multiple congenital anomalies, including central nervous system, ocular, cardiac, renal, and/or genital malformations and limb defects. Most patients show severe intrauterine groth retardation, hypotonia, failure to thrive and developmental delay. It is usually associated with miscarriage.
BILATERAL OPTIC NERVE COLOBOMAS IN INFANT WITH TETRAPLOIDY.
Beck KD, Harper CA 3rd. Retin Cases Brief Rep. 2016;10(3):252-3.
This 23-day-old male infant was born at full term and found to have tetraploidy with numerous congenital anomalies including bilateral optic nerve colobomas, left microphthalmia, vitreous hemorrhage, and septo-optic dysplasia.
