1.1 Birt-Hogg-Dubé Syndrome
Birt-Hogg-Dubé (BHD) syndrome (OMIM 135150) is a rare, autosomal dominant, hamartoma disorder which is characterized by benign tumours of the hair follicle (fibrofolliculomas), lung cysts and pneumothorax (collapsed lung), and renal neoplasia. BHD was first described in 1977 by three Canadian doctors – Birt, Hogg and Dubé (Birt et al. 1977). The syndrome had also been identified 1975 by Hornstein and Knickenberg (Hornstein & Knickenberg 1975) and there has been suggestion of renaming the disease to Hornstein-Birt-Hogg-Dubé, however due to confusion this name was never used.
A genome-wide linkage analysis using polymorphic microsatellite markers on a large Swedish family in 2001 mapped the BHD-associated locus to
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suggested that fibrofolliculomas arise from sebaceous glands rather than the hair follicles. They found that most of the epithelial strands making up the lesion are continuation of the sebaceous glands. This could possibly be as a result of ciliary dysfunction in either the sebaceous gland progenitor or stem cells, which in turn could explain the formation of skin lesions around the areas rich in sebaceous glands such as the nose and perinasal skin (Vernooij et al. 2013).
In 2010, Cocciolone et.al. suggested a connection between desmoplastic melanoma and BHD in a 58 year old patient as a result of mTOR up-regulation. There are 6 other cases of melanoma reported in patients with a BHD mutation; although quite possibly the event could be coincidental and a direct link cannot be confirmed (Cocciolone et al. 2010)(Leter et al. 2008).
The range of skin manifestation in BHD patients varies. Some patients do not develop any skin abnormalities at all whereas the number of fibrofolliculomas in other patients can differ from under 10 to over 100 (Toro et al. 1999).
Some skin abnormalities seen in BHD patients are quite similar to a few other genetic disorders shown in table
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in a study of 152 patients from 49 families in 1999 first described the presence of pulmonary cysts in BHD patients (Toro et al. 1999). Most of BHD patients are likely to develop pulmonary cysts and are susceptible to recurrent spontaneous pneumothorax. The study of 50 BHD families showed 88% of the families developed pulmonary cysts and 53% of the families had a history of pneumothorax. In another study, Toro et al. reported a 93% pulmonary cyst presence in BHD patients (Toro et al. 2007)(Toro et al. 2008). Pulmonary cysts are the most common BHD manifestation, seen in up to 90 % of patients (Predina et al. 2011). It has been suggested that the number of pulmonary cysts correlates with episodes of spontaneous pneumothoraces. Zbar et al. identified an increase in the risk of pneumothorax for BHD-affected individuals, which they postulated to be due to the presence of pulmonary cysts (Zbar et al.
In addition to symptoms of ADHD being present by the age of seven the symptoms must affect the person’s life in a number of settings. In addition the symptoms have to not be explained by another mental disorder. If it only occurs alongside a psychotic mood disorder it is not considered ADHD. Inattention in ADHD is classified as making easily avoidable mistakes and ignoring details, usually do to not paying attention. It can happen in any number of settings( Surman, 2013). For example an accountant suffering from some of the innatention aspects of ADHD may not notice they forget to put a decimal point in a number resulting in a much higher number then shoud have been expected. The average adult may catch the mistake but someone someone with at least part of the innatetion aspect will likely move on without a thought in the world. Hyperactivity is demonstrated by inabiltiy to sit still and the need to get up from one's seat to move around. Impulsivity shows itself in a person's inabilty to resist acting on their urges. Usually the person will jump in front of others in a conversation. the person may at random pick up things and start messing with them. For a person to be diagnosised with ADHD a number of the DSM-IV-TR's critera must be met.
What are the most common genetic/chromosome changes related to this form of cancer? Which genes are responsible? Where are these genes located? How are the genes different from normal individuals?
Not all ADHD conditions are created equal. There are actually two ADHD types and another that combines them to make a third type.
Distortion of the facial features can take place in a newborn with this disorder due to the thick plates of skin
In recent years, the number of children diagnosed as AD/HD has increased drastically—more than four million children5 ((5)). Statistics behind the disorder are rather shocking:
Birt-Hogg-Dube syndrome is a rare disorder where you have certain tumors. Most tumors appear on the face, forehead, and neck. BHD is caused by mutations in the FLCN gene. (Genetics Home Reference) BHD is also inherited from parents or the grandparents. The symptoms are, tumors on face, neck, and the forehead. (Genetics Home Reference) BHD increases the risk of getting cancer.
In other words, they are chunks of DNA that are either missing or duplicated. “Thapar goes on to explain that these missing or duplicated chunks of DNA are in the areas of the chromosome that overlap with those implicated in autism and schizophrenia” (DeNoon). Therefore , ADHD and Autism are very related because of the similar characteristics they share. Lastly, Thapar elaborates on how she “found out the most significant excess of these copy number variants was in a specific region that includes genes for brain development” (DeNoon). Thapar and others were able to collect data from over 350 children to prove their data. In addition, “Scientists from the National Institute of Mental Health identified individuals with ADHD have thinner tissue in the areas of the brain associated with attention” (Healthline). Those with ADHD serves from having thinner tissues around their brain. For example, kids with ADHD havse difficult times in school because of they are easily distracted, hard to keep organized and has hard times remembering assignments. Those that are born with thicker tissues around the brain, have a easier lifestyle than those with ADHD. However, “First-degree relatives of patients with ADHD are two to eight times more likely to develop ADHD than a person who has no first-degree relatives with ADHD. Boys are two times more likely to be affected than girls” (Block). Out of every 8th
These three types are caused by different gene mutations. EB Simplex is caused by autosomal dominant mutations in the genes responsible for keratin 5 and 14. Keratins are proteins that give the epidermis its structural support. These mutations can cause the skin to fall apart and cause blisters. It can cause people to loose hair and teeth. It is also the least dangerous type of EB. Junctional EB is caused by mutations in genes that “encode the proteins collagen 17 or laminin-5” (Fallon). These proteins help hold the skin together, and if they are absent, the skin would separate and blister. It can cause skin to shrink, and affected infants may not survive due to massive infection and dehydration. Dystrophic EB is caused by mutation in the COL7A gene that “produces collagen 7” (Fallon). It can also cause under skin blistering, and can have blisters in the mouth, esophagus, and digestive tract, which can make eating very
ADHD is a psychological disorder in which the individual shows one or more of the
Think of times you have observed preschool children. Did many of these students exhibit characteristics similar to those used to identify students with ADHD? Have you observed a young child who exhibited these behaviors at such an extreme level that you thought he or she might be identified with ADHD?
Birt-Hogg Dubé (BHD) syndrome is a rare autosomal dominant condition that’s characterized by the development of benign skin tumors and lung cysts. Moreover, these manifestations increase patients’ risk to develop renal cell carcinoma (RCC) and/or pneumothorax. Germline mutations in the Folliculin (FLCN) gene are responsible for patients to express the clinical hallmarks of BHD. Most of the BHD patient population contain mutations in the FLCN gene at exon 11, a disease-causing mutational hotspot. Research has shown mutations in FLCN are predicted to cause truncations of the gene resulting in its loss-of-function, resembling the function of a tumor suppressor. Furthermore, BHD clinical hallmarks are similar to the clinical manifestation caused by mutations in tumor suppressor, TSC1/2, such as: facial hamartomas and RCC. Although FLCN is predicted to be a tumor suppressor, the exact function of FLCN still remains unknown.
Ectodermal dysplasia is not a single disorder, but a group of syndromes all deriving from abnormalities of the ectodermal structures.More than 150 different syndromes have been identified.Despite some of the syndromes having different genetic causes the symptoms are sometimes very similar. Diagnosis is usually by clinical observation often with the assistance of family medical histories so that it can be determined whether transmission is autosomal dominant or recessive.Worldwide around 7,000 people have been diagnosed with an ectodermal dysplasia condition. Some ED conditions are only present in single family units and derive from very recent mutations. Ectodermal dysplasias can occur in any race but are common in caucasians than any other group and especially in fair caucasians.Ectodermal dysplasias are described as "heritable conditions in which there are abnormalities of two or more ectodermal structures such as the hair, teeth, nails, sweat glands, salivary glands, cranial-facial structure, digits and other parts of the body.
:Albinism is a autosomal recessive disease, which means that a person must have two copies of the defective gene to exhibit symptoms of the disease. The child therefore inherits one defective gene responsible for making melanin from each parents. Because the task of making melanin is complex, there are many different types of albinism, involving a number of different genes.A defect in one of several genes that produce or distribute melanin causes albinism. The defect may result in the absence of melanin production, or a reduced amount of melanin production. The defective gene passes down from both parents to the child and causes albinism.albinism:Until recently, prenatal diagnosis of OCA I was achieved by histologic and electron microscopic
HCM encompasses several aetiological factors that contribute to the development of the pathology. Most studies show that more than 55% of HCM cases worldwide are a genetic-specific cause. However, regardless of the genetic mutation being the most prevalent HCM aetiology, there are individuals with clinical diagnosis of HCM where there’s an apparent absence of mutations or without genetic involvements (acquired). (Cirino and Ho, 2014) Although autosomal recessive, X-linked, and mitochondrial trait of inheritance can also occur, the most documented mode of transmission of Familial HCM is via an autosomal dominant Mendelian pattern of inheritance. This means of an affected parent, one copy of the mutated gene in the autosomes in each cell is sufficient
Birt-Hogg Dubé (BHD) syndrome is a rare autosomal dominant condition that’s characterized by the development of benign skin tumors and lung cysts. Moreover, these manifestations increase patients’ risk to develop renal cell carcinoma (RCC) and/or pneumothorax. Germline mutations in the Folliculin (FLCN) gene are responsible for the onset of BHD, resulting in its loss-of-function. Furthermore, BHD clinical hallmarks are similar to the clinical manifestation caused by mutations in tumor suppressor, TSC1/2, such as: facial hamartomas and RCC. Although FLCN is predicted to be a tumor suppressor, the exact function of FLCN still remains unknown.