Digenic Inheritance Flashcards
____ refers to the situation in w/c the clinical condition can arise from the interaction of two different genes.
Digenic inheritance
An example of digenic inheritance is ____.
autosomal recessive non - syndromic deafness
While autosomal recessive non - syndromic deafness may result from mutations in the ____, the condition can also result from the inheritance of a single mutation in this gene together w/ a deletion in the ____.
connexin 26 gene; connexin 30 gene (both lie in chromosome 13 only 35 kb apart
Perhaps not surprisingly, the protein products of connexin 26 and 30 functionally interact, together participating in the formation of a multi – subunit ____ in the cochlea, necessary for the regulation of potassium in the inner ear.
hemichannel;
The phenotype of this condition includes truncal obesity, hypogenitalism, renal dysfunction, polydactyly, retinal dystrophy & learning disability, and there has been some debate regarding the possible role of digenic triallelic inheritance in this condition.
Bardet - Biedl syndrome (BBS).
The underlying cellular defect in BBS lies within the ____. The defect appears to particularly affect the important ____ transport system that is responsible for the movement of particles from the basal body to the tip of the cilium.
cilia; intraflagellar
At least ___different BBS - causing genes have been identified to date.
12
In most individuals affected by BBS, mutations in both alleles of a single gene, usually, ____ appear to be sufficient to cause the disease. However, in a minority of cases, the presence of 3 mutant BBS alleles, w/ the additional mutant allele most frequently involving ____ or ____ is detected in affected patients.
BBS1; BBS2; BBS6
This apparent digenic triallelic inheritance may alternatively be regarded, however, as ____.
autosomal recessive inheritance w/ a modifier of penetrance.
