Noll, I stand corrected. 😊
Obviously — I am misusing the term “compound heterozygosity” (and I wondered about that, as I wrote it). Perhaps “tri-allelic recessive heterozygosity” is a better term. Or, as the authors have in the title of their publication, simply “oligogenic inheritance.”
Oligogenic inheritance of a human heart disease involving a genetic modifier
Nebert, Daniel (nebertdw)
Thu 6/20, 12:48 PM
Noll, I stand corrected. 😊
Obviously — I am misusing the term “compound heterozygosity” (and I wondered about that, as I wrote it). Perhaps “tri-allelic recessive heterozygosity” is a better term. Or, as the authors have in the title of their publication, simply “oligogenic inheritance.” 😊
DwN
Nebert, Daniel (nebertdw)
Wed 6/19, 1:09 PM
Don, I don’t blame you; this might be considered as genetics at its most complex level. 😊
Let me try to condense this information into one crisp kernel —
The father has two variants (in his MRTFB and MYH7 genes) and is “affected but asymptomatic” (i.e. does not have the full-blown disorder). This trait, left ventricular noncompaction (LVNC), is expressed as a gradient, and the father does show the serious disease (congestive heart failure) that one sees during infancy when the trait is 100% penetrant.
The mother has one variant (in her NKX2-5 gene) and is unaffected (i.e. has a normal heart). The affected child was unfortunate to inherit all three of these variants from the two parents, which, when combined, resulted in the full-blown disorder of LVNC — manifested as severe congestive heart failure during the first two months of life.
This is an excellent example (in medical genetics) of “compound heterozygosity” (the condition of having two or more heterozygous recessive alleles, at different chromosomal loci, that can cause the genetic disease in a heterozygous state, when all necessary alleles are inherited in the same unlucky offspring). I don’t know why, but these are the kinds of things that medical geneticists get all excited about. 😉
DwN
😊
DwN