How do you tell if a disorder is SEX-Linked
- Thread starter axp107
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Foghorn
For sex-linked
Assuming father carries normal/wild type sex chromosomes
X dominant with XX mom (she has the disorder) ----> all progeny get it (the disorder)
X dominant with Xx mom (she has the disorder) ------> half of all progeny get it
x recessive with Xx mom (unaffected) ------>female progeny are normal, half of males get it
x recessive with xx mom (affected)-------->female progeny are normal, all of males get it
You can make up other scenarios where the father carries the abnormal chromosome that's dominant/recessive. And also do F1, F2 etc generations.
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If men are affected and never carriers and women are mostly carriers and very rarely affected, it's an X-linked disorder.
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the big giveaway that I usually see is if you see a majority of one sex getting the disease, i.e. usually males since they only get one copy of the X chromosome and 1 of Y.
hence they have a higher probability of expressing a sex-linked trait. their mother usually doesn't express the disease since she has 2 copies of X chromosomes, and if its recessive, her dominant copy will prevent her from expressing the disorder.
I dunno about sex-linked dominant traits, i'm sure they're out there but I've never heard anything about it.
sorry if this doesn't make sense, i'm pretty tired lol 😴
edit: just saw foghorn's post...great summary of the possibilities
hence they have a higher probability of expressing a sex-linked trait. their mother usually doesn't express the disease since she has 2 copies of X chromosomes, and if its recessive, her dominant copy will prevent her from expressing the disorder.
I dunno about sex-linked dominant traits, i'm sure they're out there but I've never heard anything about it.
sorry if this doesn't make sense, i'm pretty tired lol 😴
edit: just saw foghorn's post...great summary of the possibilities
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Prominent calluses on the hands and "chafing of the willy".
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Well said.
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Prominent calluses on the hands and "chafing of the willy".
Well said.
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Just to elaborate, there are two more cases (which don't assume that the father is normal!):
X dominant with X father (he has the disorder) ----> Daughters get it (the disorder)
X recessive with xx father (he has the disorder) and Xx mother (she seems normal) ----> half female progeny have it, half males have it (the disorder)
X dominant with X father (he has the disorder) ----> Daughters get it (the disorder)
X recessive with xx father (he has the disorder) and Xx mother (she seems normal) ----> half female progeny have it, half males have it (the disorder)
