CID Genetic Disorders

Huntington's, Sickle Cell, and CF

What is a mutation?

A mutation is any permanent, heritable change in the DNA base sequence of an organism.

• Mutagens: Agents that cause mutations

• Ionizing radiation, for example X-rays, gamma rays and alpha particles

• UV light

• Spontaneous mutation

Autosomal Dominant Inheritance

• males and females are affected

  • Huntington’s disease

  • Marfan’s syndrome

  • achondroplasia

  • neurofibromatosis

Huntington’s Disease

Is a progressive brain disorder that causes uncontrolled movements, emotional problems, and loss of thinking ability (cognition).

• adult-onset (most common)

• appears in 30s-40s

Huntington’s early signs and symptoms.

Early signs and symptoms can include irritability, depression, small involuntary movements, poor coordination, and trouble learning new information or making decisions. Many people with Huntington disease develop involuntary jerking or twitching movements known as chorea.

Huntington’s Disease developed signs and symptoms.

As the disease progresses, these movements become more pronounced. Affected individuals may have trouble walking, speaking, and swallowing. People with this disorder also experience changes in personality and a decline in thinking and reasoning abilities. Individuals with the adult-onset form of Huntington disease usually live about 15 to 20 years after signs and symptoms begin.

What is the juvenile form of Huntington’s Disease?

A less common form of Huntington disease known as the juvenile form begins in childhood or adolescence.

• also involves movement problems and mental and emotional changes

• additional signs include slow movements, clumsiness, frequent falling, rigidity, slurred speech, and drooling

• school performance declines as thinking, and reasoning abilities become impaired

• seizures occur in 30 percent to 50 percent of children with this condition

• usually live 10-15 years after signs and symptoms appear

Treatment of Huntington’s Disease

There is currently no cure or treatment which can halt, slow or reverse the progression of the disease. However, there are many treatments and interventions that can help to manage HD symptoms. A neurologist, psychiatrist, or nurse with expertise in HD may prescribe medications to ease anxiety and depression, help with troublesome behaviors, and calm uncontrolled movements.

• psychologist

• physical therapist

• clinical researchers

• friends and family or caregivers

Autosomal Recessive Inheritance

• males and females equally affected

• sickle cell anemia

• cystic fibrosis

Sickle Cell Anemia

SCD is a group of inherited red blood cell disorders. Healthy red blood cells are round, and they move through small blood vessels to carry oxygen to all parts of the body. In someone who has SCD, the red blood cells become hard and sticky and look like a C-shaped farm tool called a “sickle”. The sickle cells die early, which causes a constant shortage of red blood cells. When they travel through small blood vessels, they get stuck and clog the blood flow. This can cause pain and other serious problems such infection, acute chest syndrome and stroke.

How is SCD diagnosed?

SCD is diagnosed with a simple blood test. It most often is found at birth during routine newborn screening tests at the hospital. In addition, SCD can be diagnosed before birth.

Genetic Disorder Cystic Fibrosis

• People are born with CF

• Inherited from a recessive gene from each parent

• People with CF produce an abnormal, or unusual form of a protein called CFTR

Cystic Fibrosis Transmembrane Reductance

• First discovered in 1989

• Changes the way chloride moves in and out of cells

• Affects the balance of salt and water in the body

• A proper balance of salt and water keeps mucus thin and slippery

• CFTR causes a change in the movement of chloride and the result is thick sticky mucus

US CF Statistics

• Affects 30,000 people

• 2,500 babies born each year

• 1 in every 3,500 Caucasian births

• 1 in every 12,163 Non-White births

• 12 million carry the CF gene

CF Ongoing Lung Problems

• Painful lung infections

• Bronchial tubes can become infected and swollen

  • Bronchitis

  • Inflamed bronchial tubes

  • Bronchiectasis

    • Causes bleeding in the lungs

CF Digestive System Affects

• Thick mucous clogs pancreas

• Further blocks enzymes from moving to intestine

• Can not digest fatty foods

• Body grows and develops slowly

• Weight loss and weakness

• Can not handle infections

CF and Sweat Glands

• found in most areas of body, most commonly:

  • bottom of feet

  • palm of hands

• each person has 2 million

• two-five times the normal amount of salt in their sweat

Lack of salt in the body causes…

• tiredness

• weakness

• fever

• muscle cramps

• stomach pain

• vomiting

• dehydration

• balance of minerals in blood is affected

Male Reproductive System with CF

•Sterile

•Vas deferens do not develop

•Can still produce normal sperm

•Surgery may permit ability to father children

Female Reproductive System with CF

•Can give birth but chances are lower

•Hard to get pregnant

•Hard to remain pregnant

•Some can not get pregnant…

•Thick mucus completely blocks sperm from reaching egg

Other Signs and Symptoms of CF

•Frequent sinus infections

•Lack of energy

•Smaller height/weight than average

•Frequent dehydration and exhaustion

•Finger Clubbing

•Nasal polyps or masses inside nose

•Sound congested, Nasal voice

Diagnosis of CF

• difficult

• ASAP

• average age = 2

  • but can be as late as adult years

Steps for Diagnosis of CF

1) Medical history

• Person’s past health

• Serious illnesses among family       members

2) Physical exam

• BP, temp, HR, breathing

3) Laboratory Tests

Laboratory Tests for CF

• Most common = Sweat test

  • Measures amount of salt or sodium chloride in a persons’ sweat

  • CF confirmed if greater than (60 mmol/L)

• Chest x-rays

• Gene, pancreas, sputum and pulmonary function tests

Treatment Options for CF

• chest physical therapy

  • clapping on back or chest

  • vibrating vest

• oral or inhaled aerosolized antibiotics

• pulmozyme

  • Mucus thinning drug shown to reduce the number of lung infections and improve lung function

• inhaled anti-asthma therapy

• dietary vitamin supplements

  • especially A and D

• more