Question

Neurofibromatosis type 1 (NFl: also known as von Recklinghausen disease) is an inherited dominant disorder. The phenotype usually involves the production of many skin neurofibromas (benign tumors of the fibrous cells that cover the nerves).

a. Is it likely that NF1 is a tumor-suppressor gene or an oncogene?

Answer 1

NF1 likely functions as a tumor-suppressor gene. Inheritances of neurofibromatosis type 1 follow an autosomal dominant pattern, where offspring have a 50 percent chance of inheriting the disorder from a heterozygous parent.

Step-by-step explanation:

Neurofibromatosis type 1 (NF1), also known as von Recklinghausen disease, is an autosomal dominant disorder characterized by the creation of multiple skin neurofibromas and other nervous system tumors. Given that NF1 typically suppresses tumor formation, it is likely that the NF1 gene functions as a tumor-suppressor gene rather than an oncogene. If the NF1 gene is mutated in such a way that its tumor-suppressing ability is compromised, this can lead to the development of neurofibromas.

In the context of an autosomal dominant disorder such as NF1, a child has a 50 percent chance of inheriting neurofibromatosis when one parent is heterozygous (Nn) and the other is homozygous for the normal gene (nn). This inheritance pattern can be demonstrated using a Punnett square, which shows the likelihood of each possible genotype.