Hemizygous definition

[laczlacylaci]

Does a Hemizygous male always mean they are affected?

Ex.
X-linked recessive disorder.
Father is hemizygous->XaY<-affected
Mother is heterozygous->XAXa<-unaffected carrier

X-lined dominant disorder
Father is hemizygous->XAY<-affected
Mother is heterozygous->XAXa<-affected

Hemizygous is never present in autosomal recessive or dominant, correct?

Doesn't hemizygous basically equal to affected individual in this case.... Is it just another way to say it.

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[DrDarce]

Hemiazygous means there's only one copy of the gene instead of the normal two copies. So for males, yes they are hemizygous for all genes that are on the X chromosome - and if they have the bad gene (X-linked disorder) they will be affected whether it is recessive or dominant.

It's not normally present in autosome's unless I guess there is some special case like monosomy or something (in which case there will be other problems).