Kabuki Syndrome

Kabuki syndrome is a rare, multisystem disorder characterized by multiple abnormalities including distinctive facial features, growth delays, varying degrees of intellectual disability, skeletal abnormalities, and short stature.The specific symptoms associated with Kabuki syndrome can vary greatly from one person to another. The first gene is KMT2D (formerly MLL2) and the second gene, which accounts for fewer cases of Kabuki syndrome, is KDM6A. Clinical genetic testing is available for both genes. Kabuki syndrome was first reported in medical literature in 1981 by Japanese physicians. The disorder was originally called Kabuki-makeup syndrome because the facial features of many affected children resembled the makeup used by actors in kabuki, a form of Japanese theater. The term “makeup” has since been dropped and the preferred term for the disorder is Kabuki syndrome.

Signs and Symptoms

Some symptoms of Kabuki syndrome are present at birth (congenital). Other symptoms become apparent as an affected child ages. Children with Kabuki syndrome have a distinctive facial appearance, which includes abnormally long openings between the eyelids (palpebral fissures), lower eyelids that are turned outward (everted), prominent eyelashes, arched eyebrows, a broad nose with a flattened or depressed tip, and large, misshapen ears. The distinctive facial appearance associated with Kabuki syndrome develops slowly over several years. Additional facial features include a bluish tinge to the whites of the eyes (blue sclerae), drooping of the upper eyelid (ptosis), misaligned eyes (strabismus), a highly arched roof of the mouth or a cleft palate, depressions involving the inside of the lower lips (lip pits), and an abnormally small jaw (micrognathia). Growth deficiency is common in individuals with Kabuki syndrome usually becoming apparent during the first year of life (postnatal growth deficiency). Growth deficiency can become more noticeable as affected children grow older. In addition to growth deficiency, children with Kabuki syndrome may also have mild to moderate intellectual disability. Severe intellectual disability is extremely rare and some children have no intellectual disability. Some children may have seizures, diminished muscle tone (hypotonia) and microcephaly, a condition in which the circumference of the head is abnormally small.

Causes

Kabuki syndrome is a genetic condition that may be caused by a mutation in the KMT2D gene (in up to 80% of cases) or the KDM6A gene. In some people with Kabuki syndrome, the cause is unknown. The KMT2D gene gives the body instructions to make an enzyme called lysine-specific methyltransferase 2D, which is present in many parts of the body. This enzyme modifies proteins called histones, which attach to DNA and give chromosomes their shape. By adding a molecule called a methyl group to histones (a process called methylation), the enzyme helps to control the activity of certain genes. It appears to activate certain genes that are important for development. The KDM6A gene gives the body instructions to make an enzyme called lysine-specific demethylase 6A. This enzyme helps to remove methyl groups from certain histones. Like lysine-specific methyltransferase 2D, this enzyme also helps to control the activity of certain genes. Research suggests that the two enzymes work together. Mutations in either of these genes result in the absence of the related enzyme, which disrupts histone methylation and impairs the activation of certain genes needed for normal development.

Kabuki syndrome is a rare genetic disorder and it estimates suggest that Kabuki syndrome occurs in about one in every 32,000 births. However, Kabuki syndrome is thought to be underdiagnosed, so it could be more common. The condition affects males and females equally, and there is no cure. Kabuki syndrome is difficult to diagnose for three main reasons, every child with the condition presents with a slightly different set of characteristics, instead of being present at birth, characteristics may develop over time, and many doctors may not be familiar with Kabuki syndrome because the condition is so rare. Since Kabuki syndrome is so rare, there is limited information on the long-term outlook.

Sites:

https://rarediseases.org/rare-diseases/kabuki-syndrome/

https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/kabuki-syndrome

Congenital Heart Disease

Congenital heart disease (congenital heart defect) is one or more abnormalities in your heart's structure that you're born with. This most common of birth defects can alter the way blood flows through your heart. Defects range from simple, which might cause no problems, to complex, which can cause life-threatening complications.Some congenital heart defects cause no signs or symptoms. For some people, signs or symptoms occur later in life. They can recur years after you've had treatment for a heart defect.

Researchers aren't sure what causes most congenital heart disease, which develops in the womb. Heredity might play a role in some congenital heart disease.The heart is divided into two chambers on the right and two on the left. To pump blood through the body, the heart uses its left and right sides differently. The right side of the heart moves blood to the lungs through certain blood vessels (pulmonary arteries). In the lungs, blood picks up oxygen and then returns to the left side through the pulmonary veins. The left side of the heart then pumps the blood through the aorta and out to the rest of the body. Congenital heart disease can affect any of the heart's structures, including valves, chambers, the wall of tissue that separates the chambers (septum) and arteries.

Certain environmental and genetic risk factors might play a role in the development of your heart defect, including German measles (rubella). Your mother having had rubella while pregnant could have affected your heart development. Diabetes: Your mother having type 1 or type 2 diabetes might have interfered with the development of your heart. Gestational diabetes generally doesn't increase the risk of developing a heart defect. Medications. Taking certain medications while pregnant can cause congenital heart and other birth defects. They include isotretinoin (Amnesteem, Claravis, others), used to treat acne; and lithium, used to treat bipolar disorder. Drinking alcohol while pregnant also contributes to the risk of heart defects. Heredity. Congenital heart disease appears to run in families and is associated with many genetic syndromes. For instance, children with Down syndrome often have heart defects. Genetic testing can detect Down syndrome and other disorders during a baby's development. Smoking: A mother who smokes while pregnant increases her risk of having a child with a congenital heart defect.

Congenital heart disease complications that might develop years after the initial treatment include Abnormal heart rhythms (arrhythmias). Arrhythmias occur when the electrical impulses that coordinate heartbeats don't function properly, causing your heart to beat too fast, too slowly or irregularly. In some people, severe arrhythmias can cause sudden cardiac death if not treated. Heart infection (endocarditis): Your heart comprises four chambers and four valves, which are lined by a thin membrane called the endocardium. Endocarditis is an infection of this inner lining, which generally occurs when bacteria or other germs enter your bloodstream and lodge in your heart. Untreated, endocarditis can damage or destroy your heart valves or trigger a stroke. Stroke: A stroke occurs when the blood supply to a part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen. A congenital heart defect can allow a blood clot to pass through your heart and travel to your brain. Heart failure: Heart failure, also known as congestive heart failure, means your heart can't pump enough blood to meet your body's needs. Some types of congenital heart disease can lead to heart failure. Pulmonary hypertension: This is a type of high blood pressure that affects the arteries in your lungs. Some congenital heart defects cause more blood to flow to the lungs, causing pressure to build and making your heart work harder. This eventually causes your heart muscle to weaken and sometimes to fail. Heart valve problems. In some types of congenital heart disease, the heart valves are abnormal.

Site:

https://www.mayoclinic.org/diseases-conditions/adult-congenital-heart-disease/symptoms-causes/syc-20355456

Down Syndrome

In every cell in the human body there is a nucleus, where genetic material is stored in genes. Genes carry the codes responsible for all of our inherited traits and are grouped along rod-like structures called chromosomes. Typically, the nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome. A few of the common physical traits of Down syndrome are low muscle tone, small stature, an upward slant to the eyes, and a single deep crease across the center of the palm – although each person with Down syndrome is a unique individual and may possess these characteristics to different degrees, or not at all.

For centuries, people with Down syndrome have been alluded to in art, literature and science. It wasn’t until the late nineteenth century, however, that John Langdon Down, an English physician, published an accurate description of a person with Down syndrome. It was this scholarly work, published in 1866, that earned Down the recognition as the “father” of the syndrome. Although other people had previously recognized the characteristics of the syndrome, it was Down who described the condition as a distinct and separate entity. In recent history, advances in medicine and science have enabled researchers to investigate the characteristics of people with Down syndrome. In 1959, the French physician Jérôme Lejeune identified Down syndrome as a chromosomal condition. Instead of the usual 46 chromosomes present in each cell, Lejeune observed 47 in the cells of individuals with Down syndrome. It was later determined that an extra partial or whole copy of chromosome 21 results in the characteristics associated with Down syndrome. In the year 2000, an international team of scientists successfully identified and catalogued each of the approximately 329 genes on chromosome 21. This accomplishment opened the door to great advances in Down syndrome research.

Regardless of the type of Down syndrome a person may have, all people with Down syndrome have an extra, critical portion of chromosome 21 present in all or some of their cells. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome. The cause of the extra full or partial chromosome is still unknown. Maternal age is the only factor that has been linked to an increased chance of having a baby with Down syndrome resulting from nondisjunction or mosaicism. However, due to higher birth rates in younger women, 80% of children with Down syndrome are born to women under 35 years of age. There is no definitive scientific research that indicates that Down syndrome is caused by environmental factors or the parents’ activities before or during pregnancy. The additional partial or full copy of the 21st chromosome which causes Down syndrome can originate from either the father or the mother. Approximately 5% of the cases have been traced to the father.

Site:

https://www.ndss.org/about-down-syndrome/down-syndrome/

Autism

Autism spectrum disorder (ASD) is a neurological and developmental disorder that begins early in childhood and lasts throughout a person's life. It affects how a person acts and interacts with others, communicates, and learns. It includes what used to be known as Asperger syndrome and pervasive developmental disorders. It is called a "spectrum" disorder because people with ASD can have a range of symptoms. People with ASD might have problems talking with you, or they might not look you in the eye when you talk to them. They may also have restricted interests and repetitive behaviors. They may spend a lot of time putting things in order, or they may say the same sentence again and again. They may often seem to be in their "own world."

According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), a guide created by the American Psychiatric Association used to diagnose mental disorders, people with ASD have difficulty with communication and interaction with other people, restricted interests and repetitive behaviors, Symptoms that hurt the person’s ability to function properly in school, work, and other areas of life.

People with ASD have difficulty with social communication and interaction, restricted interests, and repetitive behaviors. The list below gives some examples of the types of behaviors that are seen in people diagnosed with ASD. Not all people with ASD will show all behaviors, but most will show several. Social communication or behaviours may include making little or inconsistent eye contact, tending not to look at or listen to people, rarely sharing enjoyment of objects or activities by pointing or showing things to others, failing to, or being slow to, respond to someone calling their name or to other verbal attempts to gain attention, having difficulties with the back and forth of conversation, often talking at length about a favorite subject without noticing that others are not interested or without giving others a chance to respond, having facial expressions, movements, and gestures that do not match what is being said, having an unusual tone of voice that may sound sing-song or flat and robot-like, having trouble understanding another person’s point of view or being unable to predict or understand other people’s actions

Restrictive / repetitive behaviors may include, repeating certain behaviors or having unusual behaviors. For example, repeating words or phrases, a behavior called echolalia, having a lasting intense interest in certain topics, such as numbers, details, or facts, having overly focused interests, such as with moving objects or parts of objects, getting upset by slight changes in a routine, being more or less sensitive than other people to sensory input, such as light, noise, clothing, or temperature. People with ASD may also experience sleep problems and irritability. Although people with ASD experience many challenges, they may also have many strengths, including, being able to learn things in detail and remember information for long periods of time, Being strong visual and auditory learners, excelling in math, science, music, or art.

https://www.nimh.nih.gov/health/topics/autism-spectrum-disorders-asd/index.shtml

https://medlineplus.gov/autismspectrumdisorder.html