In contrast to these potentially increased risks, rare X-linked recessive conditions are thought to occur less frequently in XXY males than in XY males, since these conditions are transmitted by genes on the X chromosome, and people with two X chromosomes are typically only carriers rather than affected by these X-linked recessive conditions. Cognitive and developmental
Some degree of language learning or reading impairment may be present, and neuropsychological testing often reveals deficits in executive functions, although these deficits can often be overcome through early intervention. Also, delays in motor development may occur, which can be addressed through occupational and physical therapies. XXY males may sit up, crawl, and walk later than other infants; they may also struggle in school, both academically and with sports. It is estimated that 10% of those with Klinefelter syndrome are autistic.Additional abnormalities may include impaired attention, reduced organizational and planning abilities, deficiencies in judgment (often presented as a tendency to interpret non-threatening stimuli as threatening), and dysfunctional decision processing.Compared to individuals with a normal number of chromosomes,  males affected by Klinefelters syndrome may display behavioral abnormalities. These are phenotypically displayed as higher level of anxiety and depression, and mood dysregulation. These neurocognitive abnormalities are most likely due to the presence of the extra X chromosome, as indicated by studies carried out on animal models carrying an extra X chromosome. Cause
Klinefelter syndrome is not an inherited condition. Maternal age is the only known risk factor.
External links
Scapoli, L; Girardi, A; Palmieri, A; Testori, T; Zuffetti, F; Monguzzi, R; Lauritano, D; Carinci, F (2012). "Microflora and periodontal disease". Dental Research Journal. 9 (Suppl 2): S202–6. doi:10.4103/1735-3327.109755 (inactive 31 July 2022). PMC 3692174. PMID 23814584. {{cite journal}}:  CS1 maint: DOI inactive as of July 2022 (link)


== References ==