Short Answer 
Neurofibromatosis type 1 (NF1) is a genetic disorder caused by mutations in the NF1 gene on chromosome 17, leading to uncontrolled cell division and tumor formation. It is inherited in a manner where a child has a 50% chance of inheriting the disorder if a parent has NF1, influenced by dominant and recessive alleles, with key genetic terms like homozygous and heterozygous helping to understand inheritance patterns.
Step 1: Understand Neurofibromatosis Type 1 (NF1)
Neurofibromatosis type 1, or NF1, is a genetic disorder caused by mutations in the NF1 gene, located on chromosome 17. This gene is essential for producing a protein that regulates cell division, preventing uncontrolled growth. When mutations occur, it results in uncontrolled cell division, leading to the formation of tumors.
Step 2: Genetic Inheritance and Expression
The genotype you inherit from your parents influences your physical traits, known as the phenotype. Traits are determined by alleles, with dominant alleles overpowering recessive ones. A child of a parent with NF1 has a 50% chance of inheriting the disorder, and individuals with recessive alleles can be carriers without displaying symptoms, potentially passing the trait to their offspring.
Step 3: Definitions of Genetic Terms
In genetics, specific terms define the variations of alleles. When two identical alleles are present, the individual is termed homozygous. Conversely, if the individual has two different alleles, they are heterozygous. Understanding these definitions is crucial in determining how traits are inherited and expressed in individuals affected by genetic disorders like NF1.