The symptoms of 49,XXXXY are slightly similar to those of
Klinefelter syndrome and
48,XXXY, but they are usually much more severe.
Aneuploidy is often fatal, although the effect of the additional gene dosage is greatly reduced due to
lyonization, leaving 3
Barr bodies.
Physical Males with 49,XXXXY tend to have numerous skeletal anomalies. These skeletal anomalies include: •
Genu valgum •
Pes cavus • Fifth finger
clinodactyly The effects also include: 49,XXXXY may also be associated with increased rates of
primary immunodeficiency.
Cognitive and developmental Much like
Down syndrome, the mental effects of 49,XXXXY syndrome vary. Impaired speech and maladaptive behavioral problems are typical. One study looked at males that were diagnosed with
48,XXYY,
48,XXXY and 49,XXXXY. They found that males with 48,XXXY and 49,XXXXY function at a much lower cognitive level than males their age. These males also tend to exhibit more immature behavior for their chronological age; increased aggressive tendencies were also cited in this study. Tests using the
Social Responsiveness Scale-2 (SRS-2) found that while those with the condition generally showed more signs of social impairment, there was minimal effect on their social awareness. == Pathophysiology ==