Ge Ne Ti Cs

Hi! My name is Danielle! I'm an undergraduate at Michigan State University studying Genetics & Genomics. I'm super fascinated by genetic diseases so this blog will be showcasing some rare genetic diseases! 

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Cartilage-hair Hypoplasia

Another day, another disease of the day! Today we are going to be talking about cartilage-hair hypoplasia. This is a bone growth disorder that is most prominently characterized by dwarfism, or short stature. People with cartilage-hair hypoplasia may also have other skeletal abnormalities, fine and sparse hair, and abnormal immune system function. This is a spectrum disorder which means that there is a range of conditions associated with the disease.

Starting with dwarfism, people with cartilage-hair hypoplasia often have very short limbs and a small stature, starting at birth. It is common that they will have malformations in the cartilage near the end of long bones such as arms and legs. Many people with cartilage-hair hypoplasia are very flexible in some joints but may have problems elsewhere, like extending their elbows. The malformation in this cartilage affects the development of the bone itself.

The hair of people with cartilage-hair hypoplasia is often lighter in color as well as much thinner than usual because some of the core of each hair is missing. This makes the hair look very sparse, unusually thin and very light-colored. It is possible that their skin may also be very light in color and have misshaped nails and dental abnormalities.

Abnormal immune system function is common in people with cartilage-hair hypoplasia. However, the extent varies from case to case. The more severe immune problems are categorized as severe combined immunodeficiency (SCID). People diagnosed with SCID have almost no immune protection from bacteria, viruses, or fungi. People with SCID often have repeated and persistent infections which can be serious or even life-threatening. For those who have cartilage-hair hypoplasia but not SCID, they may experience infections of the respiratory system, ears, and sinuses. Some people may even have autoimmune disorders which is when the immune system malfunctions and attacks the healthy tissues and organs in the body. People with cartilage-hair hypoplasia are also at an increased risk for developing various cancers.

All of the symptoms seen in cartilage-hair hypoplasia are caused by mutations in the RMRP gene. The RMRP gene does not code for a protein but rather a molecule called a noncoding RNA. This RNA attaches to several proteins which forms an enzyme complex called mitochondrial RNA-processing endoribonuclease (RNase MRP). This enzyme helps to copy the DNA that is found in mitochondria. It also processes ribosomal RNA which is required for assembling amino acids into functioning proteins. Lastly, this enzyme help to control the cell cycle which is how it replicates itself. Mutations in the RMRP gene will result in a noncoding RNA that is unstable. This means that it cannot bind to the proteins that it needs to in order to form the RNase MRP enzyme complex. This will interfere with its ability to carry out all of the important things that it does in the cell. This is what causes all the symptoms in people with cartilage-hair hypoplasia.

Cartilage-hair hypoplasia is an autosomal recessive inheritance pattern. This means that there needs to be mutations in both copies of the RMRP gene. This allows for some people to be carriers of the disease without showing symptoms.

Treatment is different for everyone based on the symptoms that the individual is displaying. Surgery may be needed to help individuals with significant cartilage and bone deformations. Surveillance is also important to make sure that serious damage is prevented where possible. For those who have immune deficiency, treatments include dealing with symptoms of infections as the person gets them. People with SCID may even undergo a bone marrow transplant.

Sources: https://ghr.nlm.nih.gov/condition/cartilage-hair-hypoplasia#,

https://www.ncbi.nlm.nih.gov/books/NBK84550/

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IPF: Scars in the Lungs

Welcome back! I hope you have enjoyed my last couple of blog posts! Today we have another interesting disease to explore. Today we are going to be talking about idiopathic pulmonary fibrosis (IPF). Pulmonary fibrosis is the formation of scar tissues deep in the lungs. When scar tissue forms in the lungs, the lungs cannot properly move oxygen into the bloodstream. This has many negative side effects as other organs and the brain don’t get the oxygen that they need. A person is diagnosed with IPF when doctors cannot find a cause for the fibrosis in the lungs.

Idiopathic pulmonary fibrosis is most common in middle-age or older adults. This disease can have very fast onset, slow onset, or be very steady for many years. The signs and symptoms develop over time so it is possible that they may not even appear until the disease has done irreversible damage to your lungs. The damage is only likely to get worse over time.

Sometimes doctors can trace a certain cause for pulmonary fibrosis. This may be due to exposure to environmental pollutants such as inorganic and organic dust. There are also several medicines that are known to cause pulmonary fibrosis. Some of these medications include nitrofurantoin, amiodarone methotrexate and bleomycin. However, if the cause of the scarring is unknown, it is categorized as IPF. It is thought that something inside or outside of the lungs actually attacks them over and over. These attacks harm the lungs and cause scarring between the air sacs which makes it very difficult for oxygen to pass through the air sacs into the blood stream. It is believed that genetics, cigarette smoking, and certain viral infections play a role in IPF.

There is not a set cure for IPF but there are a couple different options that may ease the pain. Certain medications may aid in this. However, there are not medications that will actually slow the progression of IPF. Many of the medications that have been used to attempt to treat IPF are anti-inflammatory, immune system suppressers, or antioxidants. Doctors may prescribe any of these medications individually or as a combination to try to find the best outcome. Other things such as oxygen therapy pulmonary rehabilitation, and lung transplant that may help to treat the symptoms of IPF. Oxygen therapy can help to reduce the shortness of breath that may happen with IPF which can allow you to be more active. Likewise, pulmonary rehabilitation may include exercise training, nutritional counseling, and breathing strategies to help manage the disease. Pulmonary rehabilitation is now a very common treatment for people with chronic lung disease to improve their overall well-being. It is possible that a lung transplant be recommended with worsening conditions. However, transplant lists are very long and hard to meet every criteria required. For people with IPF, treatment is ongoing as it constantly changes with any changes in their condition.

IPF can be a very scary disease. With no known cause and no cure, the best way to treat the disease is to manage pain so the person can have as close to a normal lifestyle as they can. However, as symptoms get worse, this becomes less possible. Many people only live about three to five years after diagnosis.

Source: https://www.nhlbi.nih.gov/health-topics/idiopathic-pulmonary-fibrosis

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Achondrogenesis: 1A, 1B, & 2

Hey guys, we’re back with another disease of the day! Today we’re going to be talking about achondrogenesis. Achondrogenesis is an extremely dangerous disease that affects infants. Due to the severity of the condition, most infants die before or shortly after birth.

Achondrogenesis is a group of disorders that affect the cartilage and bone development. Infants with achondrogenesis usually die before birth or die soon after due to respiratory failure. It is rare that some infants live for a short time after birth. This is normally only with the help of medical support. The characteristics of achondrogenesis are a small body, short limbs, and other skeletal abnormalities. Achondrogenesis is usually diagnosed during pregnancy with further testing to distinguish between the three types. These different types are distinguished by the sign and symptoms.

The three types of achondrogenesis are type 1A, type 1B, and type 2. Type 1A and 1B are the more similar of the three. Type 1A causes infants to have extremely short limbs, narrow chest, short ribs, and a lack of normal bone formation in the skull and spine. The TRIP11 gene provides the instructions for the making of a protein called GMAP-210. This protein plays an important role in the Golgi apparatus. Mutations in the TRIP11 alter the GMAP-210 and therefore alter the structure and function of the Golgi apparatus. This is what could lead to problems with bone formation as commonly seen in type 1A.

Type 1B causes extremely short limbs, a narrow chest, and rounded abdomen. The fingers and toes are often short and the feet may turn in and upward. Type 1B is caused by mutations in the SLC26A2 gene. This gene is responsible for making proteins that aid in the development of cartilage and its conversion to bone. This is what causes the skeletal problems that is seen in type 1B. This mutation prevents bones from properly forming.

Type 2 causes short arms and legs, narrow chest with short ribs, and underdeveloped lungs. There is also a lack of ossification in the spine and pelvis as well as an enlarged abdomen. Facial features include a prominent forehead, and small chin. Type 2 is a combination of 1A and 1B and is caused by mutations in the COL2A1 gene. This gene makes a protein that forms type II collagen. This collagen is what is found in cartilage. Cartilage is essential for the development of bones and connective tissues that support the body. Without COL2A1 working properly, bones and other connective tissues do not form properly.

Achondrogenesis type 1A and type 1B have an autosomal recessive inheritance. This means that a person would need both copies of the TRIP11 or SLC26A1 gene in order to have the mutations. Achondrogenesis type 2 is an autosomal dominant inheritance because they only need one copy of the mutant gene. There are no treatments that can cure achondrogenesis. Rather, treatments focus on relieving pain. It is recommended that families affected by achondrogenesis seek genetic counseling.

Due to the sensitivity of this disease, I will not be including a picture of the characteristics. Achondrogenesis causes serious deformations and complications in infants. Achondrogenesis type 2 occurs in approximately 40,000 to 60,000 newborns.

Sources: https://ghr.nlm.nih.gov/condition/achondrogenesis#diagnosis, https://rarediseases.info.nih.gov/diseases/2882/achondrogenesis

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Why You Should Know the Signs of Marfan Syndrome

Time for another disease of the day! Today we’re going to be talking about Marfan syndrome. Marfan syndrome is a connective tissue disorder. Connective tissue is important because it provides strength and flexibility to various parts of your body including bones, muscles, ligaments, blood vessels and heart valves.

Marfan syndrome is caused by mutations in the FBN1 gene. This gene provides instructions for making the protein, fibrillin-1. This protein attaches to other fibrillin-1 proteins to form microfibrils. These become part of the fibers that provide strength and flexibility to connective tissue. Microfibrils also bind to growth factors and release them at certain times to control growth and repair of tissues and other organs throughout the body. A mutation in the FBN1 gene can decrease the amount of fibrilin-1 that is available which may lead to overgrowth and instability in tissues throughout the body. This condition is an autosomal dominant disease which means that you only need one copy of the mutant gene to cause the disorder. You are at a higher risk for Marfan syndrome if someone in your family has previously been diagnosed with Marfan syndrome. Marfan syndrome affects both men and women equally.

Marfan syndrome may affect many systems in the body but often causes abnormalities in the heart, blood vessels, eyes, bones, and joints. The biggest features of Marfan syndrome are dislocated lenses in the eyes which causes vision problems and defects in the aorta which is responsible for distributing blood from the heart to the rest of the body. The aorta can weaken and stretch, causing an aneurysm in the blood vessel. Stretching of the aorta may cause it to leak which could lead to tears in the wall of the aorta which could be life threatening. People with Marfan syndrome may also have leaks in other valves in the heart which could cause irregular heartbeat, shortness of breath, and fatigue.

The most recognizable characteristic of people who have Marfan syndrome is that they are tall and slender. They often have elongated fingers and toes, which is known as arachnodactyly as well as a disproportionate arm span. Other symptoms may include a long and narrow face, crowded teeth, loose joints, scoliosis, flat feet, nearsightedness, stretch marks not related to weight loss or weight gain, and a sunken or protruding chest.

Treatment may include medication to keep their blood pressure low in order to reduce additional strain on the aorta. People with Marfan syndrome may require regular monitoring to make sure that their symptoms do not progressive to a dangerous level. Some people with Marfan syndrome may require surgery to repair the aorta or other tissues and bones.

If you suspect that you or someone you know may display some of the features common to Marfan syndrome, see a doctor or specialist for evaluation. It is important to diagnose Marfan syndrome early on. Many people with Marfan syndrome can live a normal life. Regular check-ups can make sure that symptoms do not increase to a more dangerous situation that may not be detectable from the outside.

Image: http://www.philipcaruso-story.com/marfan-syndrome/

Sources: https://ghr.nlm.nih.gov/condition/marfan-syndrome, https://www.mayoclinic.org/diseases-conditions/marfan-syndrome/symptoms-causes/syc-20350782

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All About Spina Bifida

Hi guys! Today we’re going to be starting disease of the day! This is a segment that I’m going to be starting to frequently talk about different rare diseases. You may be familiar with some, but I’m hoping you will still be able to learn something new!

The first disease that I’m going to talk about is spina bifida. Many of you may have heard of this disease before but I’m going to go more in depth about the causes, symptoms and treatments.

Spina bifida is a type of neural tube defect that affects the spine. This condition occurs when the spinal cord does not form and close as it normally should. Spina bifida can often be diagnosed during pregnancy through different screenings tests or at birth. Milder forms may not be diagnosed until later in childhood or adulthood.

There are three common types of spina bifida: spina bifida occulta, meningocele, and myelomeningocele. Myelomeningocele is the most serious type of spina bifida. This occurs when a sac of fluid forms in an opening in the baby’s back with the spinal cord and leads to sever disabilities throughout the person’s life. Meningocele is a less serious form of spina bifida when a sac of fluid comes through the baby’s back but the spinal cord is not included. This normally does not cause much damage with only minor disabilities. Spina bifida occulta is the mildest form where there is a small gap in the spine but there is no sac of fluid. This often does not cause disabilities and sometimes is not even found until later into childhood or adulthood.

The causes of spina bifida are somewhat unclear. It is believed that there are specific genetic factors as well as some possible environmental factors. While these need to be studied further, it is possible for pregnant women to reduce the risk of having a baby with spina bifida. It is recommended that pregnant women take folic acid supplements to help reduce the risk of their baby being born with spina bifida since this condition occurs in the first few weeks of pregnancy.

Treatment is different for each individual based on type and severity of their spina bifida. Many people with spina bifida are able to lead a normal life, however there are some cases where this is untrue. Myelomeningocele and meningocele often require surgeries and treatment over the span of the person’s life to help with the condition. Some people may have limited function or even paralysis in some parts of their body that may be irreversible. These cases are more rare but all the same, this condition can be very dangerous in regards to its direct effects or second-hand conditions as a result of spina bifida.

I hope you learned something new about spina bifida in this post! My baby cousin that was just born in September was born with meningocele. He is only three months old and has already had many surgeries to fix the sac that had formed on his back and to help with some complications that this caused, particularly in the formation of his brain.

Image: http://ib.bioninja.com.au/options/option-a-neurobiology-and/a1-neural-development/spina-bifida.html

Source: https://www.cdc.gov/ncbddd/spinabifida/facts.html