Rosacea – Genetics Home Reference

The causes of rosacea are complex and not well understood. Both genetic and environmental factors appear to influence the disorder, although many of these factors have not been identified.

Studies suggest that rosacea is associated with abnormalities of blood vessels (the vascular system) and the immune system. In people with this condition, blood vessels expand (dilate) too easily, which can cause redness and flushing of the skin. Rosacea is also associated with abnormal inflammation. Inflammation is a normal immune system response to injury and foreign invaders, such as bacteria. Abnormal inflammation impairs the skin’s ability to act as a protective barrier for the body. Researchers believe that a combination of blood vessel abnormalities, abnormal inflammation, and a disruption of the skin barrier underlie the signs and symptoms of rosacea.

Among the genes thought to play roles in rosacea are several genes in a family called the . The HLA complex helps the immune system distinguish the body’s own proteins from proteins made by foreign invaders. Each HLA gene has many different variations, allowing each person’s immune system to react to a wide range of foreign proteins. Certain variations in HLA genes likely contribute to the abnormal inflammation that is characteristic of rosacea.

Another group of genes that appear to be involved in the development of rosacea are glutathione S-transferases (GSTs). The proteins produced from these genes help protect cells from oxidative stress. Oxidative stress occurs when unstable molecules called reactive oxygen species (ROS) accumulate to levels that can damage or kill cells. Variants in several GST genes have been associated with an increased risk of developing rosacea. Researchers suspect that these variants reduce the ability of GSTs to protect skin cells from oxidative stress, leading to cell damage and inflammation.

Environmental (nongenetic) factors can also increase the risk of developing rosacea and trigger its symptoms. Among the best-studied risk factors for rosacea is exposure to ultraviolet (UV) radiation from the sun. UV radiation causes oxidative stress that can damage skin cells. Studies suggest that having an overgrowth of certain microorganisms that live on facial skin, particularly mites called Demodex folliculorum, may also contribute to the development of rosacea. These mites stimulate an abnormal immune response and disrupt the normal skin barrier. Other factors that can trigger the signs and symptoms of rosacea or make them worse include heat exposure, spicy food, cigarette smoking, and alcohol, all of which cause blood vessels in the skin to dilate.

Source

To find a healthcare professional, use HealthLynked. It is a first of its kind medical network built as a social ecosystem with a higher purpose – improving healthcare.  Go to HealthLynked.com to learn more, sign up for free, connect with your doctor, find a new doctor, securely store and share your health information. Download our HealthLynked app available on Apple and Android devices.

Obsessive-compulsive disorder – Genetics Home Reference

Obsessive-compulsive disorder (OCD) is a mental health condition characterized by features called obsessions and compulsions. Obsessions are intrusive thoughts, mental images, or urges to perform specific actions. While the particular obsessions vary widely, they often include fear of illness or contamination; a desire for symmetry or getting things “just right;” or intrusive thoughts involving religion, sex, or aggression. Compulsions consist of the repetitive performance of certain actions, such as checking or verifying, washing, counting, arranging, acting out specific routines, or seeking assurance. These behaviors are performed to relieve anxiety, rather than to seek pleasure as in other compulsive behaviors like gambling, eating, or sex.

While almost everyone experiences obsessive feelings and compulsive behaviors occasionally or in particular contexts, in OCD they take up more than an hour a day and cause problems with work, school, or social life. People with OCD generally experience anxiety and other distress around their need to accommodate their obsessions or compulsions.

About half the time, OCD becomes evident in childhood or adolescence, and most other cases appear in early adulthood. It is unusual for OCD to start after age 40. It tends to appear earlier in males, but by adulthood it is slightly more common in females. Affected individuals can experience periods when their symptoms increase or decrease in severity, but the condition usually does not go away completely.

Some people with OCD have additional mental health disorders such as generalized anxiety, depression, phobias, panic disorders, or schizophrenia. OCD can also occur in people with other neurological conditions such as Tourette syndrome and similar disorders, traumatic brain injury, stroke, or dementia.

Source

To find a healthcare professional, use HealthLynked. It is a first of its kind medical network built as a social ecosystem with a higher purpose – improving healthcare.  Go to HealthLynked.com to learn more, sign up for free, connect with your doctor, find a new doctor, and securely store and share your health information. Download our HealthLynked app available on Apple and Android devices.

Spastic paraplegia type 49 – Genetics Home Reference

Spastic paraplegia type 49 is part of a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by progressive muscle stiffness (spasticity) and the development of paralysis of the lower limbs (paraplegia). Hereditary spastic paraplegias are divided into two types: pure and complex. The pure types involve only the lower limbs, whereas the complex types also involve the upper limbs (to a lesser degree) and other problems with the nervous system. Spastic paraplegia type 49 is a complex hereditary spastic paraplegia.

Spastic paraplegia type 49 often begins with weak muscle tone (hypotonia) that starts in infancy. During childhood, spasticity and paraplegia develop and gradually worsen, causing difficulty walking and frequent falls. In addition, affected individuals have moderate to severe intellectual disability and distinctive physical features, including short stature; chubbiness; an unusually small head size (); a wide, short skull (); a short, ; and . Some people with spastic paraplegia type 49 develop seizures.

Problems with autonomic nerve cells (autonomic ), which control involuntary body functions such as heart rate, digestion, and breathing, result in several features of spastic paraplegia type 49. Affected individuals have difficulty feeding beginning in infancy. They experience a backflow of stomach acids into the esophagus (called or GERD), causing vomiting. GERD can also lead to recurrent bacterial lung infections called aspiration pneumonia, which can be life-threatening. In addition, people with spastic paraplegia type 49 have problems regulating their breathing, resulting in pauses in breathing (apnea), initially while sleeping but eventually also while awake. Their blood pressure, pulse rate, and body temperature are also irregular.

People with spastic paraplegia type 49 can develop recurrent episodes of severe weakness, hypotonia, and abnormal breathing, which can be life threatening. By early adulthood, some affected individuals need a machine to help them breathe (mechanical ventilation).

Other signs and symptoms of spastic paraplegia type 49 reflect problems with sensory neurons, which transmit information about sensations such as pain, temperature, and touch to the brain. Many affected individuals are less able to feel pain or temperature sensations than individuals in the general population. Affected individuals also have abnormal or absent reflexes (areflexia).

Because of the nervous system abnormalities that occur in spastic paraplegia type 49, it has been suggested that the condition also be classified as a hereditary sensory and autonomic neuropathy, which is a group of conditions that affect sensory and autonomic neurons.

Source link

To find a healthcare professional, use HealthLynked. It is a first of its kind medical network built as a social ecosystem with a higher purpose – improving healthcare. Go to HealthLynked.com to learn more, sign up for free, connect with your doctor, find a new doctor, and securely store and share your health information. Download our HealthLynked app available on Apple and Android devices.