Final answer:
Huntington's Chorea, or Huntington's disease, is an autosomal dominant disorder with a 50% chance of being passed to offspring. It leads to neural tissue damage and manifests with motor and cognitive symptoms typically in middle age. A Punnett square can be used to visualize the inheritance patterns of this disorder.
Step-by-step explanation:
Huntington's Chorea is an autosomal dominant disorder. In this genetic pattern, only one copy of the dominant allele is necessary for the disease to be expressed. Individuals carrying the allele for Huntington's disease, often represented as 'Hh,' will likely develop the disorder, typically with an onset around middle age. Since it is a dominant condition, the children of an affected individual have a 50% chance of inheriting the disorder. This can be visualized using a simple Punnett square, where the dominant allele 'H' from one parent combines with a healthy allele 'h' from the other parent, resulting in a 1:1 ratio of affected to unaffected potential offspring.
Apart from Huntington's disease, other autosomal dominant conditions include achondroplastic dwarfism and Marfan syndrome. The key aspect of these disorders is that the presence of just one defective gene causes the disease. Huntington's disease is characterized by the breakdown of neurons in the brain, leading to muscle spasms, personality changes, and a progressive decline in cognitive and motor functions. The genetic defect in Huntington's disease involves an abnormal protein with an extended glutamine sequence, which damages neural tissue over time. Diagnosis and planning are often complicated by the late onset of the disease, frequently after childbearing years.