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What is anticipation .Give examples ?
What is pleiotropy.Give example ?
what is incomplete and complete penetrance.Give examples ?
what is imprinting.Give examples ?


No body answered it sad

I know its boring but if we discuss it will become easy :idea:


smiling face ok, let's take it apart . . .

-inheritance in which the most recent generations of a pedigree develop a disease at an earlier age or w/ greater severity than in earlier generations
-can be due to gradual expansion of trinucleotide repeat.
-trinucleotide repeat expands and expands and mutations get bigger and bigger per generation
-ex: Huntington's, Fragile X, Myotonic dystrophy

-when 1 disease causing mutation affects lots of different parts of body and multiple organ systems
-ex: Marfan syndrome (just think, whole lot of stuff happens because defect in just one gene, fibrillin)

Incomplete Penetrance:
- some people who have the disease genotypically, don't show it phenotypicall, meaning no symptoms noted related to disease
-the person inherits the mutation, but doesn't show it
ex: this can be in case

Complete penetrance:
-person has the disease and shows symptoms relating to it
-in other words, disease is what it genotypically shows.
ex: likewise, can be any disease


imprinting is genes are transcriptionally active only when transmitted by one of the two sexes
-prader -willi syndrom
-angelman syndrom


thanks to both of you...

Another example of pleiotopy ( multiple effects caused by a single mutation) is osteogenesis imperfecta

What is locus heterogeneity ??


locus heterogeneity is when the same disease phenotype can be caused by mutations in different loci.e.g., in osteogenesis imperfecta,defect in type-1 collagen may be coded by either chromosome7 or 17,but one cant distinguish between disease caused by either of the two.

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