Becker Muscular Dystrophy Medical Genetics Essay

, ,

Becker Muscular Dystrophy Medical Genetics Essay

Muscular dystrophy is a familial upset that bit by bit weakens the organic structure ‘s musculuss.It is caused by incorrect or losing familial information that prevents the organic structure from doing the proteins needed to keep healthy musculuss.

There are different types of muscular dystrophies that consequence different musculuss and consequences in different grades of musculus failing. Becker Muscular Dystrophy Medical Genetics Essay.

But specifically two types are of import:

Duchenne muscular dystrophy

Becker muscular dystrophy.

Duchenne muscular dystrophy: Duchenne muscular dystrophy ( DMD ) is a terrible recessionary X-linked signifier of muscular dystrophy characterized by rapid patterned advance of musculus devolution.It is normally seen in males ( 1 in 3500 ) .

Females are largely bearers, specifically do non demo any symptoms.

The upset is caused by mutant in DMD cistron, located in human chromosome Xp21. DMD may ensue from m-RNA that contain out-of-frame displacement ( omissions, interpolations or splicing site mutants ) .This cistron codifications for Dystrophin protein, an of import structural constituent of musculus tissue. Dystrophin is responsible for linking the cytoskeleton of each musculus fibres to the underlying basal lamina through a protein complex incorporating many fractional monetary units.

Symptom: The chief symptom of DMD is a progressive neuromuscular upset, is muscle failing associated with musculus blowing with the voluntary musculuss being affected, particularly pelvic and calf musculuss.

Awkward mode of walking, running or stepping

Frequent falls

Fatigue

Skeletal malformations ( scoliosis )

Increased lumbar hollow-back, taking to shortening of hip-flexor musculuss

Pseudohypertophy of the calf musculuss

Cardiacmyopathy is common

Grower ‘s mark is seen in people who has terrible damage of lower appendages.

DUCHENNE MUSCULAR DYSTROPHY ( DMD ) is a familial disease in which the musculus of a patient ( male child ) suffers progressive harm, due to miss of dystrophin protein. Becker Muscular Dystrophy Medical Genetics Essay. It is a long unwellness in which the musculuss of a patient become bit by bit weaker and it later effects indispensable mechanism ( respiratory system, nervous system, bosom etc ) of the organic structure taking finally to decease of the DMD patient during early Twentiess ( 15 + year. )

ORDER A PLAGIARISM-FREE PAPER NOW

Diagnosis:

Deoxyribonucleic acid trials

Prenatal trials

Muscle biopsy

Deoxyribonucleic acid trials: The musculus -specific isoform of the dystrophin cistron is composed of 79exons, and DNA testing and analysis can normally place the specific type of mutant of the coding DNAs that are affected.DNA trial confirms the diagnosing in most instances.

Prenatal trials: If one or both parents are bearers so there is a opportunity of inheriting to the following coevals, for this there are some antenatal trials. At 11-14 hebdomads of gestation chorionic villous sampling, at 15 hebdomads amniocentesis, at 18 hebdomads foetal blood sampling is done.

Muscle biopsy: A little sample of musculus tissue is taken with a scalpel and a dye is applied that reveals the presence of dystrophin.

Creatine kinase ( CPK-MM ) degrees will be high in blood watercourse.

Familial testing can uncover familial mistakes in Xp21 cistron.

Treatment:

Corticosteroids such as Pediapred and deflazacort addition strength and energy of musculuss.

Beta -2 agonists besides increase musculus strength

Physical therapy is helpful to keep strength, flexibleness, and map

Orthpaedic contraptions ( such as braces and wheelchairs ) may better mobility and self-care

Stem cell replacing. Becker Muscular Dystrophy Medical Genetics Essay.

Case survey: An 18-month-old male child was referred for neuromuscular rating and intervention following a visit with the household ‘s community baby doctor. Earlier lab work had revealed a Creatine Kinase ( CK ) degree of over 15,000 – consistent with neuromuscular disease. The male child ‘s female parent reported a household history of Duchenne Muscular Dystrophy ( DMD ) on her side. She has older kids, including another male child who is unaffected.

Evaluation by a brain doctor, including a musculus biopsy, indicated the presence of DMD.

The male child was referred to a paediatric rehabilitation medical specialty doctor for farther rating. Physical scrutiny showed the kid ‘s musculus tone was decreased, and he had pseudohypertrophy ( enlargement ) of his calf musculuss. He had full scope of gesture in his weaponries and legs, and was walking by himself. His female parent reported that he began walking at about 14 months of age. Although he moved reasonably good from sitting to standing, he did utilize a modified Gowers manoeuvre ( forcing up with his custodies on his articulatio genuss and legs, with his underside up, to accomplish a standing place ) . This is typical with Duchenne dystrophinopathy, bespeaking lower appendage failing around the hips and articulatio genuss. Neck musculus and upper appendage strength was satisfactory.

The kid ‘s cognitive map appeared to be normal, and he was synergistic. His female parent reported that he participates good in age-appropriate activities with his equals. However, she did notice that he tired more easy than other kids his age.

These findings are characteristic for DMD at an early age. The doctors discussed the kid ‘s hereafter with his parents, including possible intervention options as his disease progresses. Becker Muscular Dystrophy Medical Genetics Essay. Those options include assistive devices ( such as braces and mobility devices ) , physical and occupational therapy appraisals and intervention, and drug therapy.

A familial counsellor interviewed the household and arranged for molecular familial testing to see if the kid has a cistron omission associated with DMD. Familial testing can assist nail the exact nature of DMD, every bit good as aid place if other household members could be affected. Referrals were besides made to societal services, to assist both the kid and his household place their strengths and demands within their community.

As portion of the intervention program, the doctors recommended that the kid return to the neuromuscular clinic every six to twelve months for re-evaluation and necessary intercessions as he grows and develops. Timely intercessions, to assist forestall or decelerate complications related to DMD, will assist the kid maintain the best possible quality of life and might increase length of service. The male child was scheduled to undergo baseline testing of his strength, scope of gesture and functional ability by one of the healers the following clip he returns to clinic. Baseline proving can assist set up current map, every bit good as quantify the demand for and effectivity of specific interventions. Future baseline testing by cardiology and pulmonology services can besides assist the determination devising procedure. Becker Muscular Dystrophy Medical Genetics Essay.

BECKER MUSCULAR DYSTROPHY:

Becker muscular dystrophy is similar to Duchenne muscular dystrophy, but is less common and progresses more easy. This affects about 1 in 30,000 male childs than in females. This is a familial X-linked disease characterized by the change of the distrophin cistron merchandise, a structural protein of import for keeping unity of skeletal and cardiac musculus cell cytoskeleton. Changes are normally due to inframe omissions or point mutants of the distrophin cistron, which is located on the chromosome Xp211.

The skeletal musculus in this patient besides showed about all of the histological characteristics of Becker muscular dystrophy, including mortification, regeneration, endomysial fibrosis, dividing fibres and unnatural fluctuation in fiber size.

Cardiac failure is the most common cause of decease in Becker muscular dystrophy patients.Becker Muscular Dystrophy Medical Genetics Essay. It is postulated that impaired myocardium leads to an increased work load on the left ventricle, leads to go forth ventricular expansion and mitral valve distension. This patient had terrible myocardiopathy with left and right ventricular expansion and mitral and tricuspid valve distension. Pulmonary vascular thickener suggests the presence of left bosom failure with subsequent development of pneumonic high blood pressure taking to right ventricular distension and possible right bosom failure.

Symptoms:

Many childs with muscular dystrophy can follow normal form of development during first few old ages of life. But in clip the symptoms began to look. A kid with MD may get down to falter, toddle, hold trouble in traveling upstairs, and a toe walk.

A kid may get down to fight to acquire up from sitting place or hold difficult clip in forcing things like waggon.

Childs with MD develops enlarged calf musculus ( pseudohypertrophy ) as musculus tissue is replaced by fat.

Frequent falls

Trouble in running, hopping, leaping

Loss of musculus mass

Breathing jobs

Congestive bosom failure

Loss of balance and coordination, weariness

Trials:

CPK blood trial

Electromyography ( EMG ) nervus proving

Muscle biopsy or familial blood trial

Diagnosis: The trials to find what type of MD is involved and to govern out other diseases that could do the job.

These might include a blood trial to step degrees of serum creatine kinase, an enzyme that ‘s released into the blood stream, when musculus fibres are deteriorating.Becker Muscular Dystrophy Medical Genetics Essay.

Elevated degrees indicate that something is doing musculus harm.

The physician besides may make a blood trial to look into the Deoxyribonucleic acid for cistron abnormalcies or a musculus biopsy to look for forms of impairment and unnatural degrees of dystrophin, a protein that helps muscle cells maintain their form and length.

There are several major signifiers of muscular dystrophy, which can impact the musculuss to changing grades. In some instances, MD starts doing musculus jobs in babyhood ; in others, symptoms do n’t look until maturity.

There is no remedy for MD. Doctors are working on bettering musculus and joint map and decelerating musculus impairment so that those with MD can populate as actively and independently as possible.

Treatment: There is no known remedy for Becker muscular dystrophy.

The end of intervention is to command symptoms to maximise the life of the affected individual.

Doctors prescribe steroids to assist maintain a patient walking for every bit long as possible.

Activity is encouraged. Inactivity ( such as bed remainder ) can do the musculus disease worse.

Physical therapy may be helpful to keep musculus strength.

Orthopedic contraptions such as braces and wheelchairs may better mobility and self-care.

Familial guidance may be recommended. Daughters of a adult male with Becker muscular dystrophy may transport the faulty cistron and could go through it onto their boies. Becker Muscular Dystrophy Medical Genetics Essay.

Examples:

( dual heterozygote ) :

Becker muscular dystrophy and X-linked colour sightlessness

Jonathan, a 10-year-old male child, has Becker muscular dystrophy and colour sightlessness. His female parent, Mary, has normal colour vision, but her two brothers and maternal uncle have red-green colour sightlessness. Based on her household history, Mary is an obligate heterozygote, or bearer, of the X-linked cistron mutant for colour sightlessness. Molecular proving confirms that she besides carries a omission in one of her X-linked DMD cistrons, which accounts for the Becker muscular dystrophy in her boy. Though the two conditions are unrelated, Mary is known to be heterozygous at two separate venues on the X chromosome and is hence a dual heterozygote.

Case survey:

A 28 twelvemonth old adult male was admitted for haemoptysis, dyspnoea, febrility, icinesss, sickness, emesis, and icterus. At age 12 old ages, he was noted to hold scoliosis, and he described trouble running. Additional clinical findings at the clip of his first rating were enlarged calf musculuss, atrophic thoracic musculuss, elevated creatine phosphokinase degrees, every bit good as an unnatural EMG and musculus microscopy. Becker Muscular Dystrophy Medical Genetics Essay. The patient was was non followed for his status between the ages of 12 and 24 old ages. At the age of 24 old ages, echocardiography showed a badly dilated left ventricle with terrible planetary hypokinesis, mild atrial expansion, possible mural apical thrombus, and a little pericardiac gush. The patient was placed on Vasotec and Lanoxin. Repeat echocardiogram at the age of 27 old ages showed similar findings, and the patient was placed on Coumadin anticoagulation to forestall cardiac mural thrombi and emboli. Four months prior to his concluding admittance, he was hospitalized briefly for pneumonia and left ventricular bosom failure with pneumonic congestion. Given his deteriorating cardiac position, the patient was later placed on the cardiac organ transplant list two hebdomads prior to admittance.

Past medical history revealed that his younger brother was diagnosed at age 14 old ages with dilated myocardiopathy that resulted in decease three hebdomads following the oncoming of terrible acute congestive bosom failure. Two other siblings and his parents are free of bosom disease.

When admitted, the patient had haemoptysis, dyspnoea, febrility, icinesss, sickness, emesis, and icterus. His international normalized ratio on admittance was 6.6, and his white blood cell count was 16,400/uL. A chest X ray showed a mass-like consolidation of the right lower lobe of lung. He continued to hold episodes of haemoptysis, elevated white blood cell counts and elevated international normalized ratios asking Vitamin K therapy. Five yearss after admittance, the patient noted chest firing following bronchioloalveolar lavage. Shortly thenceforth, he was found to be asystolic without respirations. Cardiopulmonary resuscitation failed, and the patient died. Becker Muscular Dystrophy Medical Genetics Essay. The necropsy was limited to the thorax.

Becker muscular dystrophy (BMD) is an inherited condition that causes progressive weakness and wasting of the skeletal and cardiac (heart) muscles. It primarily affects males.^[1]^[2] The age of onset and rate of progression can vary. Muscle weakness usually becomes apparent between the ages of 5 and 15. In some cases, heart involvement (cardiomyopathy) is the first sign.^[2] BMD is caused by a mutation in the DMD gene and is inherited in an X-linked recessive manner. BMD is very similar to Duchenne muscular dystrophy, except that in BMD, symptoms begin later and progress at a slower rate.^[1]There is no cure for this condition, but there is ongoing research that shows significant promise in treating the disease. Current treatment aims to relieve symptoms and improve quality of life.^[3] People with BMD may survive into their 40s or beyond.^[1]

Symptoms

The symptoms of Becker muscular dystrophy (BMD) may begin anywhere from childhood to a person’s early 20s.^[4]^[5] Muscle weakness often affects the legs and pelvis, and slowly gets worse.^[4] Over time, affected people begin to have difficulty walking, frequent falls, difficulty with muscle skills (such as running, hopping, and jumping), and loss of muscle mass.^[3] Eventually, affected people require a wheelchair.^[5] The condition also affects the heart muscles, causing dilated cardiomyopathy. This form of heart disease enlarges and weakens the heart muscle, preventing it from pumping blood efficiently. Becker Muscular Dystrophy Medical Genetics Essay.Dilated cardiomyopathy progresses rapidly and is life-threatening in many cases.^[4] Other symptoms of BMD may include cognitive problems, fatigue, loss of balance and coordination, problems breathing, and muscle weakness in the arms, neck and other areas of the body.^[3]

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing 1-5 of 23 |

Medical Terms	Other Names	Learn More: HPO ID
80%-99% of people have these symptoms
Abnormal urinary color	Abnormal urinary colour [ more ]	0012086
Difficulty climbing stairs	Difficulty walking up stairs	0003551
Difficulty walking	Difficulty in walking	0002355
Elevated serum creatine kinase	Elevated blood creatine phosphokinase [ more ]	0003236
Exercise intolerance	Decreased ability to exercise [ more ]	0003546

Showing 1-5 of 23 |

Do you have more information about symptoms of this disease? We want to hear from you.

Last updated: 6/1/2020

Cause

Becker muscular dystrophy (BMD) is caused by specific mutations in the DMD gene. The DMD gene gives the body instructions to make a protein called dystrophin. This protein helps stabilize and protect muscle fibers and may play a role in chemical signaling within cells. Becker Muscular Dystrophy Medical Genetics Essay. Mutations that lead to an abnormal “version” of dystrophin that allow it to keep some of its function usually cause BMD. Muscle cells without fully functional dystrophin become damaged as muscles contract and relax with use. They then weaken and die over time, leading to the muscle weakness and heart problems in people with BMD.^[4]

Inheritance

Becker muscular dystrophy is inherited in an X-linked recessive manner. A condition is considered X-linked if the mutated gene that causes the condition is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one mutated copy of the gene in each cell is enough to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the condition. Males are affected by X-linked recessive disorders much more frequently than females. A specific characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.^[4]

In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. Female carriers of X-linked recessive conditions have a 50% (1 in 2) risk to pass on the mutated gene to each child. Male children have a 50% risk to be affected, and female children have a 50% risk to be a carrier. Female carriers usually do not have signs or symptoms of the condition. Occasionally, females who carry a DMD mutation may have muscle weakness and cramping.Becker Muscular Dystrophy Medical Genetics Essay. These symptoms are typically milder than the severe muscle weakness and wasting in affected males. Females who carry a DMDmutation also have an increased risk to develop heart problems, including dilated cardiomyopathy.^[4]

In about two thirds of cases, an affected male inherits the mutation from his mother who carries a mutated copy of the DMD gene. The other third of cases probably result from new mutations in the gene.^[4]

Last updated: 9/3/2016

Diagnosis

Becker muscular dystrophy (BMD) may first be suspected in a person with signs or symptoms of BMD. Healthcare providers will often conduct neurological and muscle exams, as well as order specific laboratory tests. A careful medical history is also important to differentiate between BMD and Duchenne muscular dystrophy.^[3]Exams in a person with BMD may reveal:^[3]

Abnormally developed bones, leading to deformities of the chest and back (scoliosis)
Abnormality of heart muscle function (cardiomyopathy)
Congestive heart failure or irregular heartbeat (arrhythmias)
Muscle deformities
- Contractures of heels and legs
- Fat and connective tissue (pseudohypertrophy) in calf muscles
Muscle wasting that begins in the legs and pelvis, then progresses to the muscles of the shoulders, neck, arms, and respiratory system

Laboratory tests that help confirm the diagnosis include:^[3]

CPK
Electromyography (EMG)
Muscle biopsy or genetic testing

Last updated: 9/3/2016

Testing Resources

The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional. Becker Muscular Dystrophy Medical Genetics Essay.

Treatment

There is currently no cure for Becker muscular dystrophy (BMD), and management aims to help with symptoms and improve the quality of life. Affected people are encouraged to remain active, because inactivity (such as bed rest) can make the muscle disease worse.^[3]

Physical therapy can help with stretching tight muscles and using assistive devices; occupational therapy can help with daily living skills; and speech therapy may help those with dysphagia (difficulty swallowing). Surgery may be needed for progressive scoliosisand development of contractures.^[6]

People with BMD should be monitored for orthopedic complications. Cardiac (heart) evaluations are recommended beginning at around 10 years old, or when symptoms first begin. Evaluations should be repeated at least every two years.[7242]

ORDER A PLAGIARISM-FREE PAPER NOW

Some studies have shown that certain corticosteroids (such as prednisone or prednisolone) can slow the decline of muscle strength in people with Duchenne muscular dystophy; however, information about their use in people with BMD is limited.Becker Muscular Dystrophy Medical Genetics Essay. [7242] There are a number of additional therapies for BMD being studied.[7242] Potential future treatments for BMD may include gene therapy, exon skipping, ataluren, creatine, deacetylase inhibitors, myostatin inactivation, and cell therapy (myoblast treatment, and/or the use of stem cells).^[6]^[7]

Management Guidelines

Section on Cardiology and Cardiac Surgery. Cardiovascular health supervision for individuals affected by Duchenne or Becker Muscular Dystrophy. Pediatrics 2006; 116: 1569-1573.

Prognosis

Becker muscular dystrophy (BMD) generally leads to slowly worsening disability, but the amount of disability can vary among affected people. Some men need a wheelchair, while others may only need walking aids such as canes or braces. The lifespan is often shorted due to heart disease and respiratory complications.^[8] Most people with BMD survive well into mid- to late adulthood. If the effects of the condition on the heart are mild, or if they are adequately controlled with medical intervention, a person can have a normal or nearly normal life span.^[9]

Last updated: 9/3/2016

Statistics

The incidence (rate of occurrence of new cases) of Becker muscular dystrophy (BMD) has been estimated to be between 1 in 18,000 and 1 in 30,000 male births.^[10]^[11]

Prevalence estimates (all the people affected with BMD at a given time) are relatively broad and the ranges differ depending on the source. According to Medscape Reference, the prevalence of BMD is estimated to be between 17 to 27 cases per million people.^[10]This means that at a given time, about 1 in 37,000 to 1 in 59,000 people are living with BMD. According to Orphanet, the prevalence is estimated to be between around 1 in 11,000 to 1 in 100,000.^[11]

Becker Muscular Dystrophy Medical Genetics Essay