49,XXXXY<unk>  is an extremely rare aneuploidic sex chromosomal abnormality. It occurs in approximately 1 out of 85,000 to 100,000 males. This<unk>  is the result of maternal non-disjunction during both meiosis I and II. It was first diagnosed in 1960 and was coined Fraccaro<unk>  after the researcher.
XXXXY syndrome
XXYY syndrome
XX male syndrome
XYY syndrome
XYYY syndrome
Ring chromosome 20 syndrome
Apert syndrome
XYYYY syndrome