Although leprechaunism and type A syndrome are most likely due to defects in the structure and expression of the insulin-receptor gene, they are likely to be associated with specific point mutations rather than major changes in gene structure.
Thus, we have biochemically characterized a new family of leprechaunism (Ark-2) and have found insulin receptor phosphorylation defects in their phenotypically normal parents.
Insulin receptor complementary DNA has been cloned from an insulin-resistant patient with leprechaunism whose receptors exhibited multiple abnormalities in insulin binding.
Insulin receptor complementary DNA has been cloned from an insulin-resistant patient with leprechaunism whose receptors exhibited multiple abnormalities in insulin binding.
To evaluate whether alterations in insulin receptor kinase of erythrocytes can be used as genetic markers, we studied patients with two apparently inherited conditions of severe insulin resistance (leprechaunism and the type A syndrome of insulin resistance) and their families.
In this study we analyze insulin binding and subunit structure of the insulin receptor in dermal fibroblasts cultured from three unrelated families whose probands (Ark-1, Atl, and Minn) were affected by leprechaunism.
We conclude that in this family two different recessive mutations impair high-affinity insulin-receptor binding and that the proband with leprechaunism is a compound heterozygote for these mutations.