male infant with pre-maxillary agenesis, bilateral microphthalmos, alobar holoprosencephaly, hydrocephalus, ventricular and atrial septal defects, small penis, bilateral cryptorchidism, and bilateral upper limb postaxial polydactyly." Both doctors noted no use of drugs, alcohol or cigarettes by the mother, and the baby was delivered normally after forty-one weeks of gestation. It was the first child of the parents, who were not related and went on to have another child successfully however this child was a stillbirth. There was severe overlapping of the bones of the skull and a cleft lip in addition to the bilateral polydactyly. Of the organs, Young and Madders noted missing parts of the tricuspid valve and other small cardiac defects, as well as the holoprosencephaly. Both doctors consulted various medical databases and, after discounting Meckel syndrome due to a lack of renal abnormalities, concluded that this was a hitherto unclassified condition. After later classification, it was later named for the two doctors, though at the time of publication it was termed 'pseudotrisomy 13' due to similarities with the condition Trisomy 13. Another case in 1989 with similar symptoms was also published as an example of 'pseudotrisomy 13', and there was no evidence of an extra chromosome, further suggesting that Trisomy 13 was a separate condition. Identifying chromosome thirteen Sporadic reports of the case continued, with 'pseudotrisomy 13' becoming a common term due to the similar pathology to Trisomy 13. However, there was a growing belief that unlike Trisomy 13, Young–Madders syndrome was not caused by a duplicated chromosome, and in fact the cause lay in some other fault with chromosome thirteen. In 1991 a publication in the Journal of Medical Genetics by a group of eight doctors, based on a five-patient case-study, argued that Trisomy 13 and Young–Madders syndrome were two distinct conditions and renamed the disorder to avoid confusion. Their case studies, when viewed together, suggested a recessive genetic cause, based on the repeated instances of holoprosencephaly polydactyly in the aforementioned five cases, which led to the suspicion of an anomaly in chromosome 13's genetic coding. Chromosome thirteen spans about 114 million base pairs (the building material of DNA) and represents between 3.5 and 4% of the total DNA in cells. Problems with this chromosome account for several conditions including nonsyndromic deafness, Waardenburg syndrome and Wilson's disease. The majority of the cases discussed in the journal were still born, with death occurring between twenty-six and thirty-four