Gene dosage effect
 

"A small proportion of genes remain active on the inactivated x chromosome
(lyonization) . For this reason, inheritance of an abnormal number of x chromosomes can cause clinical manifestations due to gene-dosage effect, as seen in Turner and Klinefelter syndromes."
:rolleyes:

Can anyone explain this to me, please. :plz:
Is it someing like "manifested heterozygote" ?