Baby Research Projects: Mitochondrial Disease; By Lindsay Irwin

Mitochondrial Disease

A disease that effects thousands every year. What is this disease you may ask, Mitochondrial Disease; a disease resulting from the failure if mitochondrial development. Mitocondria are responsible for creating more than 90 percent of the energy needed for ones body to substain life and growth. Less and less energy is generated in the cells and cells begin to die or work very wrong. This proccess is repeated throughout the body, and slowly the whole system begins to fail. Life of the person becomes much more challenging and eventully shorter.

Mitocondial Disease can affact any organ of the body at any age. This disease is more commonly found amongst children and babies. Disease of Mitochondria causes most damage to cells in the brain, heart, liver, skelatol muscels, kidney and endocrine and respritory system.

The effects of this disease can have symptoms in areas including:

Brain
Developmental delays Dementia Neuro-psychiatric disturbances	Migraines Autistic Features Mental retardation	Seizures Atypical cerebral palsy Strokes

Nerves
Weakness (may be intermittent) Absent reflexes	Fainting Neuropathic pain	Dysautonomia - temperature instability& other dysautonomic problems
Muscles
Weakness Cramping Gastrointestinal problems Dysmotility	Irritable bowel syndrome Hypotonia Muscle pain	Gastroesophogeal reflux Diarrhea or constipation Pseudo-obstruction
Kidneys
Renal tubular acidosis or wasting
Heart
Cardiac conduction defects (heart blocks)	Cardiomyopathy
Liver
Hypoglycemia (low blood sugar)	Liver failure
Ears & Eyes
Visual loss and blindness Ptosis Ophthalmoplegia	Optic atrophy Hearing loss and deafness	Acquired strabismus Retinitis pigmentosa
Pancreas & other glands
Diabetes and exocrine pancreatic failure (inability to make digestive enzymes)	Parathyroid failure (low calcium)
Systemic
Failure to gain weight Fatigue	Unexplained vomiting Short stature	Respiratory problems

There are about 20 different types of this disease. Inheritance in most cases is either an autosomal recessive or maternal manner, some may be speratic. Autosomal recessive inheritance may be familiar to some readers in that several non-mitochondrial disorders are inherited in this manner, including cystic fibrosis and albinism. Autosomal recessive inheritance is possibly the most common model in mitochondrial disorders. "Maternal inheritance (also known as mitochondrial or cytoplasmic inheritance) is the most complicated of all. Maternally inherited mitochondrial disorders are not rare, and possibly are as common as autosomal recessive mitochondrial disorders. All maternally inherited diseases are mitochondrial disorders. Examples include MELAS, MERRF, NARP and LHON."(umdf.org) "In X-linked disease, the genetic defect is located on the "X" chromosome and usually affects males only. This happens because females have 2 X chromosomes - 1 each from the mother and father"(umdf.org) "With dominant inheritance, only one copy of the defective gene is required in order to develop the associated disorder. This means that each person with the disorder has a 50/50 chance of passing on the gene to any children they may have. Additionally, any child that inherits the defect may develop the disorder and in turn have a 50/50 chance of passing on the defective gene. However, with one normal and one mutated gene, all of these individuals may or may not develop symptoms of disease. If they do develop disease, the severity can vary markedly. In regards to the highly variable manifestations among individuals with a defective gene, autosomal dominant and maternally inherited mitochondrial disorders are similar. However, in autosomal dominant, but never in maternally inherited, conditions boys can pass the defective gene and disease to their children."(umdf.org) However, not all mitochondrial disease is primarily genetic, Either the nuclear or mitochondrial DNA could be involved. Inheritance is probably autosomal recessive, maternal or sporadic (no inheritance), but not necessarily.

Every 30 minutes, a child is born who will develop a mitochondrial disease by age 10. Each year, 1,000 to 4,000 children in the United states are born with a mitochondrial disease. While exact numbers of children and adults suffering from mitochondrial disease are hard to determine because so many people who suffer from mitochondrial disease are frequently misdiagnosed, we now know the disease is approaching the frequency of childhood cancers . It effects both adults and children and the results can be fatal.

At this time there are no cures for these disorders, but medical professionals and scientist are working to find one. For now they have goals such as slowing down the progression of the disease and alleviate symptoms. As more research dollars are raised to find more effective treatments and ultimately a cure, some of the affected children and adults are living fairly normal lives with mitochondrial disease. On the other hand, many are severely affected, and some children do not survive their teenage years. A Foundation for this disease was created in 1996 by parents of pacients.The UMDF(United Mitochondrial Disease Foundation) exists to promote research and education for the diagnosis, treatment and cure of mitochondrial disorders and to provide support to affected individuals and families.

My 17 year old cousin has suffered and lived with this disease her entire life. As a baby she was born normal or so we thought. She began to progress and develope slower and we knew something was not right, but it was not untill she was about 1 or 2 that we had a reason. She was diagnosed with a type of Mitochondrial Disese. She has slowly gotten worse and worse over the years and is at the age mentallity of about a 9 or 10 year old. She suffers with loss of hearing and most eye sight, unstable and shakiness with some brain retardation, digestive problems and muscle faliular, etc. Doctors fight to find a cure but we are told her life outlook does not look good nor much longer. She contines to be a happy loveable girl despite her challenges. Having someone who is close to me be effected with a serious medical issue has made me realize we should be thankful for the life we have been given, even when we ourselves have challenges, it could always be worse.