Showing posts with label Genetic Disorders. Show all posts
Showing posts with label Genetic Disorders. Show all posts

Tuesday, December 13, 2011

Fragile X

Genetics of the Disorder:
Fragile X is inherited by a change in a part of a X chromosome. Most of the time mutations in a gene called FMR1 cause the Fragile X syndrome. Gene FMR1 is a gene used for holding the instructions for a protein called Fragile X mental retardation 1 protein.

Symptoms:
   Behavior includes:

  • Delay in Crawling, Walking, or Twisting
  • Hand clapping or hand bitting
  • Hyperactive behaivor
  • Mental Retardation
  • Speech and Language delay
  • And tries to avoid eye contact
   Physical Signs are:
  • Flat Feel
  • Flexible Joints 
  • Large body size
  • Large forehead or ears with prominent jaw
  • Long Face
  • Soft Skin
Signs:
  • Large Head circumference in babies
  • Mental retardation
  • Large testicles after the start of puberty
  • Small differences in facial features
Diagnosis:
To diagnose Fragile X you can get a molecular genetic testing of the FMR1 gene.

Treatment:
There is no specific treatment for Fragile X, but instead you can put them through training and education to help children with a certain needs, with lots of help.

Prevalence in the Population:
Fragile X syndrome occurs in approximately 1 in 4,000 males and 1 in 8,000 females, and occurs in all racial and ethnic groups.

Life Expectancy:
People with Fragile X have a normal life expectancy but about 15% of the boys and 5% of the girls develop seizures. 


Marfan Syndrome




Causes





  • Caused by a mutation in the FBN1 gene on chromosome 15


  • Inherited in families-autosomal dominant


Symptoms





  • Vaired among people


  • Can range from mild to severe


  • Weak connective tissues in the heart, skeleton, eyes, and other organs


  • Aorta may be larger


  • Spine may be curved


  • Eye lense might become dislocated


  • Loose joints


  • Chest bone may bend in or out


  • Bone overgrowth-long, thin arms and legs


Diagnosis





  1. Dilatated or dissected aorta


  2. Dislocated eye lense


  3. Lumbosacral dural ectasia- CT scan or MRI


  4. At least four skeletal features of the disease

  5. Close relative has the disease


Treatments




  • Eyeglasses


  • Artificial eye lense-surgery


  • Arch supports/Orthotics


  • Surgery for skeletal problems


  • Medication to decrease stress on the aorta


  • Surgery to repair the aorta


  • Blood pressure medication


  • Avoid competitive sports, isometric and statis exercise, certain medications, and caffeine


Prevalence





  • Both sexes


  • All ethnicities


  • Rare-about 1 in 10,000


Life Expectancy





  • Early to mid 70s if treated


  • In the 40s if not treated

Monday, December 12, 2011

Genetic Disorders

My genetic disorder was SMA
SMA-stands for Spinal Muscular Atrophy
Affects:
nervous system
voluntary muscle movement- like flexing an arm or a leg
Spinal:affects nerves attached to the spine
Muscular: it doesn't allow for nerves to deliver signals to muscles to work
Atrophy:the term for wastage or shrinkage which happens to the muscles when they aren't active
Causes:
deficiency-doesn't make enough or lacks-of a motor neuron protien
motor neuron
Types:
SMN related SMA
non- SMN SMA
Spinal Bulbar Muscular Atrophy-SBMA =genetic problem on the X chromosome also called kennedy's disease
Type 1 SMA(Werdning-Hoffmann disease) children live approximently 2 years after birth
Type 2 SMA(Intermidiate SMA)
Type 3 SMA(kugelberg-welander disease or mild SMA)
Type 4 SMA(Adult Onset SMA)
Problems:
1 respiratory muscle weakness
2 swallowing muscle weakness
3 back muscle weakness with progressive curvature
4 abnormal reactions to muscle-relaxing medications(anesthesia)
Treatments
1: breathing ventilation devices
2: liquid food & swallowing tube
3: Back brace
4: Use of different drugs
Who can get it:
Any one can get SMA the first types are more common in children where as the last 2 types are common in adults

Sunday, December 11, 2011

Hemachromatosis

Genetics of the Disorder- it is autosomal recessive, which means it has the ability of developing an overload of chromosomes.
Signs and Symptoms- fatigue was most common in women and diabetes was most common in men. Other symptoms were joint pain, body weakness, weight loss, and stomach pain. Not everyone who has Hemachromatosis has symptoms of the disease.
Diagnosis and Detection- Doctors look at medical history, they do physical examinations, and routine blood tests. Some types of blood tests are: Transferrin Saturation Test, Serum Ferritin Test, Liver Blopsy, and Molecular Genetic Testing.
Treatments and Therapies Available- the main idea is to rid the body of excess iron. A therapy in which they do this is called phlebotomy. A pint of blood is taken once or twice a week for several months to a year. The earlier it is treated, the better.
Prevalance in the Population- People of Northern European descent are more prone to hereditary hemochromatosis than from over ethnic backgrounds.
Life Expectancy- people with hemochromatosis have a normal life expectancy. Survival may be shortened in people who develop cirrnosis or diabetes mellitus.

Hemophilia

Hemophelia is a genetic disorder in which a persons body does not have the ability to gave their blood clot.
The body of a hemophiliac does not have the ability to produce special proteins called coagulation factors. A protein necessary for the clotting of blood. The result is unstoppable bleeding.

Symptoms
-Bleeding
-Internal Bleeding
-Bleeding to death during a surgery
- Bleeding to death during serious injury
-Internal bleeding without cause
Signs
-Abnormal bleeding occurrence
-Present in family tree
Treatment
-Injecting missing clotting factor into patient
-Extra care during surgery or other important operations

Wolf-Hirschhorn Syndrome







Wolf-Hirschhorn syndrome is a genetic disorder when there is a deletion of the short arm of chromosome 4 (shown on the image on the left). It is a contiguous gene syndrome, where chromosome is missing some materials. In most cases (90% of the time), this disorder is not inherited. The parents can have a normal arrangement of the chromosomes, but their children can inherit a chromosome 4 with missing pieces. Some get it from unusual chromosome abnormality. Depending on how much of the genetic material is missing, the symptoms vary. Deletion of genes called WHSC1, LETM1, and MSX1 are signs and symtoms of Wolf-Hirschhorn syndrome.

Signs and symptoms:

  • Small heads
  • Foot deformity
  • Greek helmet noses (broad bridges continuing to forehead)
  • Widely spread eyes
  • Metal retardation
  • High forehead
  • Arched eyebrows
  • Deformed feet
  • Seizures
  • Hearing loss
  • Skeletal abnormalities
  • Brain structure abnormalities
  • Heart defections
  • Undeveloped organs (urinary and genitals)

Diagnosis and detections:

  • Facial appearance
  • Growth delay
  • Ultrasound
  • Seizures
  • Retardation
  • X rays
  • Renal Ultrasonography (to examine kidneys and brains)
  • Chromosomal microarray (detects deletion of chromosomes)

Treatments and therapies available:

There is no specific treatment to completely heal this disorder, but there are ways to prevent some symptoms:

  • Medication
  • Gastrostomy feeding tubes
  • Orthopedic surgery
  • Valproic acid and antiepileptic drugs (for seizures)
  • Physical aids – wheel chairs, hearing aids, etc.
  • Surgery

Prevalence in population:

Wolf-Hirschhorn is a rare disorder, but can occur in all ethnicities. It is said that it occurs once every 50,000 people and occurs in females twice as many as the males. The reason for this disorder being more common in females is yet unknown.

Life expectancy:

The exact life expectancy is unknown. Most people with this disorder die right away when they’re born or die after a little while they’re born. In the past, people with this disorder died right away. But now, more people tend to live longer. The oldest person to have this disorder and be still living today is said to be around 62 years old (born in 1949). 1 out of 5 children live about 2 years and the rest live between the ages of 18 and 34.

Cri-Du-Chat


For my genetic disorder I choose Cri-Du-Chat, here is some background on it.

Cri-Du-Chat is a syndrome that makes a baby's cry sounds like one of a cat. This is a result from missing a part of the 5th chromosome. Other names for Cri-Du-Chat is cat cry syndrome, 5p minus syndrome, and chromosome 5p deletion syndrome. It is believed to develop during the egg or sperm. Symptoms of Cri-Du-Chat are downward slant to the eyes, a low birth weight and slow growth, low set or abnormally shaped ears, webbed fingers or toes, wide set eyes, small head or small jaw. There is no treatment for Cri-Du-Chat but a doctor may prescribe things that can manage the treatment. The disorder is rare. 1 in 20,000 babies are diagnosed with the syndrome a year and is found in all ethnicity's. Most children dont survive past the first few months, and 90% pass away by the first year. It is possible but rare to live longer. The longest person to live with Cri-Du-Chat lived to 60 years of age.

Cystic Fibrosis

Genetics
  • Autosomal Recessive- need 1 recessive allele from each parent or 2 copies of the mutated gene
  • Cystic Fibrosis Transmembrane Regulator (CTFR) gene
  • Chromosome 7
Symptoms                                                            Image Detail
  • Diarrhea                                                                   
  • Smelly and Greasy Stool
  • Frequent Pneumonia                            
  • Coughing
  • Salty Skin
  • Poor Growth
Diagnosis
    Image Detail
  • "Sweat Test"
    • test amount of salt in sweat on skin
  • Can be tested to see if you are a carrier (can only pick up 80% of carriers)
What is CF?
  • Gene mutation that prevents the production of a protein which allows chloride ions to pass through the cell membrane
    • This is why the skin of people with CF is saltier
  • This results in lung damage and digestive problems
Treatment
  • Enzyme supplements- lack of digestive enzymes
  • Chest percussions and other methods used to clear mucus from lungs
  • Drugs that break up mucus build up in lungs
  • When older, lung transplants can extend life expectancy
  • All lung problems can be treated but not cured
  • Gene therapies available
Prevalence and Life Expectancy
  • 1 in 2,500 in the U.S.
  • Equal between men and women
  • Most common in Caucasions and some Native Americans
  • Life Expectancy- Mid 30's 

Pachyonychia Congenita

This genetic disorder is very unique and unusual, originating from mutations in the genes KRT6A, KRT6B, KRT16, and KRT17, which supply the directions in producing keratin proteins. Keratin proteins are “tough, fibrous” proteins that give skin, hair, and nail tissues the durability and sturdiness they need. Therefore, having these mutations results in the modification of the shape of a keratin protein, which disables the proteins from building firm networks inside of the cells. These networks are essential because, without them, skin cells would be delicate and easily broken, which makes the skin not as unsusceptible to friction or slight trauma. As for the nails and hair, deformed keratins will disturb the activities and growth of cells in the nails and hair follicles. This disorder is inherited in an autosomal dominant pattern. In about “half of all cases”, an “affected” person gets the mutation from just one diseased parent, while the other half of cases are produced from brand new mutation and may occur in people who have no family history of the disorder at all.

Symptoms and Diagnosis

A sure symptom of PC would be the thickened nails. Another noticeable sign would be hurting blisters and plump calluses on soles of the feet. Other symptoms would include white swelling of the tongue, a collection of cysts, and “blisters and calluses on the palms of the hands”. However, symptoms of children are different than those in adults. Symptoms that occur in children would include lumps around hair follicles and a very raspy or croaky voice. Some symptoms are shown in the picture to the left.

As for diagnosis, there are two types of PC: type 1 and type 2. The two forms of PC can be differentiated by faintly different symptoms. However, while just looking at the symptoms can be unreliable because they can fluctuate between the two types, genetic testing can verify if a person has type 1 or type 2 since different mutated keratin genes code of one type of the other (KRT6A or KRT16 codes for type 1 and KRT6B or KRT17 code for type 2).

Treatments, Life Expectancy, and Prevalence

Currently there is no treatment for Pachyonychia Congenita. However treatments are being worked on. The brand new technology incorporating “gene silencing” has the potential to be a cure for PC in the future. On the other hand, drug therapies are in short supply. People trim and file their nails to avoid infections and soaking and massaging of the hands and feet “clean off blistered skin”. Increasingly, because of the constant pain that comes with PC, some keep the sensitive areas of the skin damp and cool for relief and canes or “special shoes” can lessen the stress on the feet (as putting just a little bit of pressure, even just when walking, on those tender areas of the feet tear skin cells).

The prevalence of PC is not known, but it seems to be remarkable rare. It is estimated that there are a few thousand people in the world living with PC. Fortunately, though, Pachyonychia Congenita does not influence lifespan.

Genetic disorders


Hello bio class!

Today I will explain the basics of Patau's syndrome, or Trisomy13. Trisomy 13 is a more specific explanation of the disorder. It literally is a third copy of the 13th chromosome in the human genome. This can cause overlapping of eyes, hands and other body parts, and other defects, and overall missing characteristics of the human structure. Most signs are visable at birth, such as the preceding symptoms, and various heart problems. The treatment depends on the symptoms. When the parents don't have the disease, the odds of a kid having it if their parents don't are about 1 in ten thousand. On average the life expectancy is less then a year, but again, it depends on the symptoms.

Neurofibromatosis by Christina P.


Neurofibromatosis is found on chromosome 17. It involves the NF1 gene which codes for the Neurofibromin protein that regulates the protein Ras (helps cell division). When the NF1 gene is mutated, the cells can't stop dividing which then forms tumors.
Neurofibromatosis is autosomal dominant and can be inherited in 2 different ways:
  • inherited from a parent, the offspring has a 50% chance of being born with the disease
  • new mutations in only some of the cells, but if the gene is mutated in the egg or sperm cell, then the parent will pass that gene down
Physical Signs and Symptoms:
  • all physical signs differ depending on the person because each person's unique genetics influences their symptoms
  • have cafA au lait spots (spots the color of coffee with cream) and freckles
  • have a lot of neurofibromas (benign tumors)
  • high blood pressure, bone defects, scoliosis, learning disabilities, Lisch nodules (benign growths on the eye), optic gliomas (benign tumors on optic nerve)
Diagnosis:
  • can be diagnosed by looking at the physical symptoms
  • if their is a family history of the mutated gene
  • genetic tests on the NF1 gene
There is NO CURE, but surgery is an option for taking out tumors. If a tumor becomes cancerous, then chemotherapy and radiation are treatment options. Ethnicity nor gender are factors in deciding who will have the disease. One in 4,000 births in the U.S. contain the mutated gene which causes neurofibromatosis. An estimated 100,000 people in the U.S. have neurofibromatosis. Surprisingly though, people with neurofibromatosis have a normal life expectancy.

Cri-Du-Chat


Cri-du-chat syndrome is caused by a deletion of a part of chromosome 5. Because of this deletion, many of the genes are nonexistent in the affected person. This deletion happens because of a break in the DNA molecule during the creation of the egg or sperm. It could be, but not always is, inherited from a parent. The symptoms of cri-du-chat is having a cat-like cry as a baby, Also the affected person has distinctive facial features like a small, unusually round head. They also have many health problems such as respiratory problems, severe mental retardation, and heart defects. Doctors can detect this syndrome by an infants cat-like cry or by some of their health problems. Doctors can also detect it when the baby is still in the mothers womb. Sadly, there are no treatments for cri-du-chat, but the child can go through therapy so that they develop as normally as possible. It is also the most common syndrome that comes from a chromosomal deletion, and about 1 in 50,000 babies are affected. The life expectancy is normal if the person has no major organ defects or critical medical conditions.


Galactoesema

Galactoesema is a rare disorder where the body cannot break down a certain enzyme called GATL. It is where the bodys lack of ability to break down a sugar called galactose. This disorder is a single gene disorder and it is also affected on chromosome 9 in the galt gene. The symptoms of this disorder is very severe. It includes kidney failure, enlarged livier, cataracts, poor growth, and mental retardnation. Galactoesema is inherited but in a milder form. A different gene that is in galactose metabolism is mutated to the next child. Babies get tested for this disorder at birth by getting a blood sample on there heal. 1 of 55,000 babies are affected with galactoesema. If there is a history of galactoesema in the family, then when a women is pregnat, the doctor can do tests to test whether the future baby will have the disorder. There is no actual treatment expect to eat a restricted diet and avoid any dairy products. This disorder doesn't affect one gender or ethnicity.

Saturday, December 10, 2011

Cystic Fibrosis


Cystic fibrosis is a genetic disorder that affects the digestive and respiratory systems. Cystic fibrosis is a recessive disorder, meaning that both parents must pass on the gene for any of their children to have the disease. If a child only gets one faulty gene, they will be a carrier. People who suffer from cystic fibrosis inherit a defective gene in their chromosome seven, also called CTFR. CTFR stands for cystic fibrosis transmembrane conductance regulator. The protein, which is produced by CTFR, helps salt move out and in to cells. If the protein doesn't work right, that movement can be blocked, and a thick layer of mucous is made on the outside of the cell. Lung cells are the most affected by this disorder. The mucous blocks the airways in the lungs, which increases the chance of infection from bacteria.

Signs and Symptoms
  • Coughing or Wheezing
  • Respiratory illnesses (pneumonia or bronchitis)
  • Weight loss
  • Salty-tasting skin
  • Greasy stools
Diagnosis and Detection
  • Have about 2-5 times the normal amount of salt in their skin (Doctor's use a sweat test to measure the amount of salt)
  • In newborns doctors can measure the amount of a protein called trypsinogen in the blood, if diagnosed with cystic fibrosis the level of protein is higher.
  • Genetic tests can identify a faulty CFTR gene, using a sample of the patient's blood.
Treatments and Therapies

Although there is no cure for cystic fibrosis, new treatments are helping people with the disease live longer than before.
  • Chest physical therapy, to free up the mucous
  • Inhaled antibiotics, to kill bacteria
  • Pancreatic enzyme replacement
  • Gene therapy, in which a healthy CTFR is inserted in to the lungs
Prevalence in the Population
  • Cystic Fibrosis is most common among Caucasians. One in twenty-five people of Europe carry one allele for the disorder.
  • Ireland has the highest Cystic fibrosis population
Life Expectancy

  • Most cystic fibrosis patients only live to be slightly more than thirty years old.

Wolf-Hirschhorn Syndrome


Wolf Hirschhorn syndrome is when a mutation occurs in the Chromosome 4 or a little piece of it is deleted or lost. This is normally not inherited. It is an accidental or natural disorder. Both parents could be healthy and have no deletion in Chromosome 4 and still have a child with the disorder because while trying to produce a zygote the chromosomes might have been rearranged or were accidentally deleted. This disorder affects peoples' physical appearance and how they are mentally as well.


Signs and Symptoms
  • Distinctive Facial features- wide set eyes, broad nose, prominent forehead
  • Slow growth
  • weak cry during infancy
  • heart defects
  • seizures
  • any form of retardation
  • difficulty to swallowing food
Diagnosis and Detection
  • Because the distinctive facial features they children that are born could be diagnosed with it just by how they look
  • Ultra sound
  • X rays by looking for bone or internal mutation
Treatments and Therapies
There is no cure for the genetic disorder directly, but there are things that could help some of the symptoms. For example, for the seizures there are medical cures for them. For food they could use a gastronomy feeding tube. For muscle strength they can go through physical therapy.

Prevalence in the Population
About 1 in 50,000 births have the disorder. It affects women more than it affects men. It occurs to all ethnic backgrounds.

Life Expectancy
The life expectancy is unknown because normally people with this genetic disorder would die as soon as they are born. But for those who survive they live to they are 45 or they live to they are 20. It is different for everyone.

Fragile X

The gene for Fragile X is carried on the X chromosome because both males (XY) and females (XX) have at least one X chromosome, who can both can pass on the mutated gene to their children. Fragile X is when a father with the altered gene for Fragile X on his X chromosome will only pass that gene on to his daughters. If he has a son, he passes a Y chromosome on to his sons, which doesn’t transmit the condition. Therefore, if the father has the altered gene on his X chromosome, but the mother’s X chromosomes are normal, all of the couple’s daughters would have the altered gene for Fragile X, while none of their sons would have the mutated gene but can still have fragile X.

Signs and Symptoms
  • Some degree of intellectual disability or learning problems
  • Behavioral problems, such as difficulty paying attention and frequent tantrums
  • Autistic-like behaviors, such as hand flapping and hand biting
  • Delays in learning how to sit, walk and talk
  • Speech problems
  • Anxiety and mood problems
  • Sensitivity to light, sounds, touch and textures
Detection and Diagnosis

Fragile X can be diagnosed using the person’s blood for the analysis of the FMR1 gene. This DNA test, available since the gene was first identified in 1991 can detect Fragile X in normal carriers and in those affected, but it cannot tell from that analysis if the child is or will be intellectually impaired or the severity of many of the symptoms.

Treatment

Standard treatment includes special education, speech, occupational, and sensory integration training; and behavior modification programs. Surgical correction of heart defects is sometimes necessary.

Life Expectancy

People with fragile X pretty much have a normal life expectancy. With having this though, they do sometime devolpe seizures which can effect their life expectancy.

Huntington's Disease

Huntington’s is a genetic brain disorder that will affect a person’s ability to think, talk, and move. It is passed down by autosomal dominant inheritance. This means that every person who inherits the diseased gene will end up getting the disease. It also means that each child will receive a normal copy of the gene from their mother and a normal or defective gene from their father. The gene for Huntington’s is found on chromosome four. In normal people their chromosome four will have the DNA sequence CAG repeating about ten to twenty six times. However, in people who have Huntington’s CAG repeats about forty or more times. Since this is so high it interferes with the function of the gene’s protein product. Yet, no one knows why the amount of CAG is so large.

Signs and Symptoms:

People who are affected by the disease don’t start showing symptoms until they are between the ages of thirty and fifty. The disease slowly worsens. Some symptoms are…

· Poor memory

· Depression or Mood swings

· Lack of coordination

· Twitching or uncontrolled movements

· Difficulty walking, speaking, or swallowing

· In later stages people need help doing very simple things such as getting dressed

Diagnosis and Detection:

When a woman is pregnant there are two different ways to find out if the baby will have the disease. One way is taking a sample from the fluid around the fetus, and the second way is to take a sample of the fetal cells from the placenta. Once the child is born doctors can test for the disease by doing neurological and psychological tests, or they can do a genetic test, which will tell if the child has the Huntington’s gene mutation. However, the genetic test cannot tell when the child will get the disease.

Treatments and Therapies:

The treatments that are out there do not slow the disease, but they can make a person who has the disease more comfortable. There are medications that can ease the feelings of depression and anxiety. Other types of medication can control the involuntary movements. There is also physical and speech therapy that can help a person with the disease live a more normal life.

Prevalence in the Population:

In the United States about one in every thirty thousand people have the disease. It is less common in Asians and Africans.

Life Expectancy:

Once a person has been diagnosed with Huntington’s disease they have about fifteen years left of their life.

Phenylketonuria (PKU)




Phenylketonuria
(PKU)
PKU is an inherited disease, starting with the parents. Each parent has two PAH genes which are located on each chromosome 12. In order to pass this genetic disease down, each parent needs to have a mutated PAH gene. This is because this disease is a autosomal recessive disorder which means in order for a child to inherit it, it needs to have two copies of the mutated gene. While producing sperm or eggs, only one of the parent's PAH genes goes into each cell, resulting in which about half of the cells would contain a mutated PAH. The offspring of who's parents are each carriers of the mutated gene would have a 1/4 chance of obtaining PKU. The child could still have one mutated PAH gene, which would make him/her a carrier, but the child does not actually have the disease unless it has both mutated genes, which is what makes this disease autosomal recessive.

Signs and Symptoms
New born babies usually do not have any signs/symptoms of this disease at first, but if not treated, it can lead to serious brain damage causing behavioral problems, epilepsy, and stunt growth of the baby. Physical symptoms can include:
  • a small head
  • fair skin
  • eczema
  • body odor
Diagnosis
PKU must be treated early, therefore every baby in the United States gets tested for this disease. What they look for in a PKU-positive baby is high levels phenylalanine in their system. They do this by a simple blood test of the baby's heel or arm. Because all babies are tested and treatment is started right away, severe symptoms of PKU are rarely seen.

Treatments
Mostly all types of protein contain phenylalanine in them, which is why people with PKU obtain a protein-free diet. As for infants, they are given a protein-free formula. People with PKU also can't have artificial sweeteners because those also contain phenylalanine. Besides having a strict diet, another treatment for PKU is an FDA approved medicine.

Prevalence in Population
Prevalence of PKU varies through ethnicity and geographic regions worldwide. In the US, PKU occurs in 1 in 10,000 to 15,000 newborns. As far as ethnicity, the groups that have higher rates are Turks, which are 1 in 2,600, and Irish, which are 1 in 4,5000. The ethnic group that has a significantly low rate of PKU is Japanese, which is 1 in 143,000. This disorder is not seen very much in Africans as well.

Life Expectancy
A person with PKU has almost the same lifespan as somebody without PKU, as long as they had followed the appropriate steps to treat their PKU correctly. This is especially important during their childhood when the brain is still developing.

Genetic Disorder - Beta-thalassemia


Beta - Thalassemia

The genetic disorder I researched was Beta-thalassemia. This is when the blood protein - beta globin - is absent from red blood cells. The red blood cells die, causing anemia. This disorder is recessive, so the person has to inherit 2 copies of the mutated beta globin gene - one from each parent.

SIGNS AND SYMPTOMS

The more severe the disorder, the more severe the symptoms will be. Carriers of thalassemia usually have no symptoms. However, if the person has the disorder, some symptoms include:


  • stunted growth

  • enlarged spleen (and other organs)

  • bone problems

  • fatigue

  • poor appetite

  • jaundice (yellowing of skin, or whites of eyes)

DIAGNOSIS/DETECTION


As you can see, thalassemia cells are not a perfect round shape, like normal red blood cells.


Beta-thalassemia can be diagnosed by taking a blood sample from an infant and looking at it under a microscope. Affected cells will appear oddly shaped and pale in color. Another test measures the MCV (mean corpuscular volume) in blood. The amount of hemoglobin in the blood can also determine if the infant has the disorder.






TREATMENTS

If a person has Beta-thalassemia, blood transfusions are needed for the individual to grow and survive. Therapy for removal of extra iron in the blood is also necessary (because the extra iron is being introduced by blood transfusions).


HOW COMMON IS THE DISORDER?

Thalassemia is most common in people from the Mediterranean, Africa, and South East Asia. In Mediterranean areas, 1 in 10 people can have Thalassemia. It is not as common in the United States; however, approximately 2 million Americans may have some form of the disorder.

LIFE EXPECTANCY

If left untreated, the life expectancy for someone with Beta-thalassemia is about 30 years of age. If the case is milder, the person can live to around the normal life span.

Thursday, December 8, 2011

Neurofibromatosis - Sonya A.

Neurofibrotomosis. It is a disorder that prevents the cell from growing. Neurofibromatosis has a gene mutation on chromosome number 17. The individual inherits this disorder from a parent. It is an autosomal dominant pattern and it also only needs one copy of the defective gene for the child to have the disorder.

The signs and symptoms of the disorder include:
  • most patients will have very visible large brown spots and freckles everywhere on the body.
  • The have noncancerous tumors called neurofibromas that may progress into a malignant tumor.
  • Others patients may have high blood pressure, bone defects, scoliosis (the curving of the spine), learning disabilities and benign growth on the iris of the eye and benign tumors on the optic nerve. The optic nerve connects the eye to the brain.
When the doctors diagnose patients who have Neurofibromatosis, they look for physical signs such as the tumors or the spots that are visible on the body. The doctors also take into account, your family history. Another method they can use is sequencing the patient's gene to find any mutations. They will not recommend genetic testing because it is very easy to confirm the disorder with physical signs and also there are no extra benefits for extra treatment at this current time.

At this point in time, there is no cure or current treatment. Although, you can surgically remove some of the tumors in your body.

In the population, Neurofibromatosis occurs 1 in every 3,000 to 4,000 people around the world. It also occurs in both genders and in all ethnic groups and ethnicities.

The life expectancy of this disorder will vary because it depends on the severity and there is no definite and concrete age that a person will live up to with the disorder.

autosomaldominant.jpg