A well-documented trisomy 13 case presenting with a number of common and uncommon features of the syndrome.

Trisomy 13 is a very rare and lethal autosomal chromosomal malformation syndrome. Its incidence is 1/12,000 births. In this paper, we present a new trisomy 13 case associated with unusual and undescribed findings. This patient was the first child of unrelated parents with advanced maternal and paternal age, at 36 and 38 years, respectively. Unfortunately, the parents did not accept the prenatal diagnosis. The baby was born after 34 weeks of gestation by cesarian section. His birth weight was 1,865 g and he demonstrated typical craniofacial abnormalities for trisomy 13 such as severe microphthalmia, microcephaly and scalp defects, and peripheral chromosome analysis revealed trisomy 13. He died of congenital heart disease and sepsis on the 12th hospital day. A complete autopsy revealed a scalp and a skull defect at the vertex, aplasia of the 5th finger nails, a complex heart disease including pulmonary trunk atresia, patent foramen ovale, membranous ventricular septal defect (VSD), main aorticopulmonary collateral artery (MAPCA) and aortic dextroposition, arrhinencephaly, partial agenesis of the corpus callosum, and neuronal heterotopias in the cerebellum. He also had bilateral cystic renal dysplasia, Meckel's diverticulum, right inguinal hernia, ectopic splenic tissue in the pancreas, and ectopic thymus tissue adjacent to the thyroid. To our knowledge, this is a unique trisomy 13 case with numerous common and uncommon features including a bone defect in the skull, partial agenesis of the corpus callosum, aplasia of the 5th finger nails, and a complex heart disease including pulmonary atresia, patent foramen ovale, membranous VSD, MAPCA and aortic dextroposition, which have not been published previously in the relevant literature all together.