Fig. 3

Possible mechanisms underlying the mosaicism in the study patient. (A) One hypothesis for the mechanism underlying the study patient’s karyotype is that a dic(Y;22) loss was followed by endo-reduplication of the remaining normal chromosome 22 (upper diagram). Alternatively, dic(Y;22) may have undergone a break at the junction followed by loss of the Y segment and telomere healing at 22p (lower diagram). (B) Predicted secondary structure following end-to-end telomere fusion. The resulting palindromic sequences have the potential to form a cruciform structure via intrastrand-base pairing of single-stranded DNA. The sequences indicated by red arrows are complementary to those indicated by blue arrows