Question

All three diseases are associated with some type of progressive disorganization of movement, which may be a gradual loss of movement or gradual increase in overt movements. Some form of tremor can be seen during some stage of all three as well. Two diseases have distinct tremor patterns that are “hallmarks” of the conditions. Affected individuals have “gait” changes, once again being quite distinct for two of the diseases. Short-term and recent memory loss are typical of Parkinson’s and Alzheimer’s diseases and often eventually for Huntington’s disease. Other common signs and symptoms include various levels of disorientation, anxiety, depression, and ultimately other symptoms of dementia.    Dysphasia is eventually seen in all three, and dysarthria is common in at least two of them communication and cognitive skills gradually deteriorate in all three.

1. Match the three diseases with the first prominent sign of each:

Memory loss of recent events:

Depression, often manic:

Muscle rigidity and slowing of overall movements:

Using the letter “H” to indicate the dominant gene for the disease and the letter “h” to indicate the recessive normal gene.

2. How would the inheritance pattern percentages differ if the trait for Huntington’s disease was recessive?

Answer 1

1

Memory loss is the most common sign of Alzhiemer's disease. It is a chronic neurodegenerative disease that usually starts slowly and gradually worsens over time. In this disease condition brain cell connctions and cells themselves degenerate and die,eventually destroying memmory power.It is the cause of 60-70% ofcases of dementia.

H-AD(APP,PSEN1, and PSEN2 and one genitic factor(APOE4 allele)

Patients suffering from Huntington disease, Depression is one of the most common psychiatric disturbance.This occurs due to inury to brain and not simply as a reaction to recieving a diagnosis.Mania also associated with same disease condition.It causes elevated mood,hyperactivity,impulsive behavior and feeling of high self-esteem.

H-HD HTT

Muscle rigidity,or the stiffness and inflexibility of limbs,neck or trunk, is one of the primary motor symptoms of Parkinson's disease.This disease is a progressive nervous system disorder that affects movements.

H-SNCA(PARK1=4) and LRRK2 (PARK8), h-Parkin(PARK2),PINK1(PARK6),DJ-1(PARK7) and ATP13A2(PARK9)

2

Huntingtons disease is caused by an inherited defect in a single gene. Inheritance is autosomal dominat only one copy of a mutated HD gene is needed to pass on the disorder, thus the chance of inheritance is 50%.