Phenotype-cytogenetic correlation in partial trisomy 13q and trisomy 18p resulting from maternal origin

A 7-day-old female neonate presented with dysmorphic features and multiple congenital anomalies displaying bilateral microphthalmia, congenital heart disease and postaxial polydactyly. Additionally, the brain MRI showed Dandy-Walker malformation, agenesis of corpus callosum, ventriculomegaly and hypoplastic brainstem. G-banded chromosome analysis showed that the child was 47,XX,t(13;18),+mar. Chromosome analysis of the parents showed that the father had a normal karyotype and that the mother had a balance between 13 and 18.

MLPA and array CGH showed that the chromosome marker was derived from 18p and 13q. array CGH revealed that the patient had partial trisomy 13q14.3q34 (53,057,362-115,107,733)x3 and partial trisomy 18p11.32p11.21(263,821-14,058,294)x3. This neonate is the first to be liveborn with a condition in which partial trisomy 13q and trisomy 18p coexist. The infant developed hydrocephalus and died at 7 months of age. This report demonstrates that array CGH is a valuable diagnostic tool in determining the origin of additional small genetic materials. Proper genetic and prenatal counseling is very important for future family planning.