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 Genetics Information: 
 sex linked disease

  Rickets 
  Hypogonadotropic
     hypogonadism 

  Diabetes insipidus; 
     nephrogenic 

  Glucose-6-phosphate 
     dehydrogenase 
     deficiency  (G-6-PD)

 
Hemophilia 
  Hemophilia A 
  Hemophilia B 
  Endometriosis 
  Muscular dystrophy 
 Chronic granulomatous 
    disease 



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 Genetics Information: sex linked disease      

"sex linked disease"
1. Rickets 

A disorder involving softening and weakening of the bones of children, primarily caused by lack of vitamin D and/or lack of calcium or phosphate.
Rickets 
Content Description:
A disorder involving softening and weakening of the bones of children, primarily caused by lack of vitamin D and/or lack of calcium or phosphate.

Causes and Risk:
Rickets is a disorder caused by insufficiency or inefficient action of activated vitamin D in the body during childhood. Vitamin D is a fat-soluble vitamin that may be absorbed from the intestines or may be produced by the skin when the skin is exposed to ultraviolet light (particularly sunlight). It is converted to its active form by the body in 2 steps, occurring first in the liver and completed in the kidneys. In its active form, vitamin D acts as a hormone to regulate calcium absorption from the intestine and to regulate levels of calcium and phosphate in the bones. Active vitamin D is assisted by the actions of other body hormones.

Because vitamin D is fat soluble, conditions that reduce digestion or absorption of fats will decrease the ability of vitamin D to be absorbed from the intestines. Sunlight is important to skin production of vitamin D, and environmental conditions where sunlight exposure is limited may reduce this source of vitamin D. Lack of vitamin D production by the skin may occur with indoor confinement or working indoors during the daylight hours, or it may occur in climates with little exposure to sunlight.

When the body is deficient in vitamin D, it is unable to properly regulate calcium and phosphate levels. If the blood levels of these minerals becomes low, the other body hormones may stimulate release of calcium and phosphate from the bones to the bloodstream.

Rickets is a bone disease of children. It causes progressive softening and weakening of the bone structure. There is a loss of calcium and phosphate from the bone, which eventually causes destruction of the supportive matrix. The parathyroid gland may increase functioning to compensate for decreased levels of calcium in the bloodstream, resulting in even more loss of calcium and phosphorous as it is reabsorbed from the bones. In severe cases, cysts may develop in the bones.

Rickets is fairly rare. It is most likely to occur during periods of rapid growth where the body demands high levels of calcium and phosphate. It is usually seen in young children 6 to 24 months old and is uncommon in newborns.

Nutritional causes of rickets occur with a lack of vitamin D in the diet or with malabsorption disorders characterized by poor fat absorption, including steatorrhea, sprue, and short bowel syndrome. A dietary lack of vitamin D may occasionally occur in people on a vegetarian diet who do not drink milk products or in people who are lactose intolerant (those who have trouble digesting milk products). A dietary lack of calcium and phosphorous may also play a part in nutritional causes of rickets. Rickets from a dietary lack of these minerals is rare because calcium and phosphorous are present in milk and green vegetables. A dietary lack of calcium causes osteoporosis (an adult disorder causing brittle bones) more often than it causes rickets.

Hereditary rickets is a vitamin D-resistant form of rickets caused when the kidney is unable to retain phosphate. It is an inherited, sex-linked disorder.

Rickets may also be caused by kidney disorders involving renal tubular acidosis. The acidic condition of the body causes the calcium in the bones to dissolve, leaving soft, weak bones.

Occasionally, rickets may be caused in children with disorders of the liver or biliary (liver secretion) system, when fats and vitamin D are inadequately absorbed or when the vitamin D is not converted to its active form.

Renal osteodystrophy occurs in people with chronic renal failure. The manifestation is virtually identical to that of rickets in children, and that of osteomalacia or osteoporosis in adults.

Prevention:
Rickets may be avoided by maintaining an adequate intake of calcium, phosphorous, and vitamin D. This may require dietary supplements in people with associated gastrointestinal or other disorders.

Renal causes of vitamin D should be treated promptly. Levels of calcium and phosphorous should be monitored regularly in people with renal disorders.

Symptoms:
bone pain or tenderness
arms, legs, spine, pelvis
skeletal deformities
bowlegs
forward projection of the breastbone (pigeon chest)
"bumps" in the rib cage ("rachitic rosary")
asymmetrical or odd-shaped skull
spine deformities (spine curves abnormally, including scoliosis or kyphosis)
pelvic deformities
increased tendency toward bone fractures
dental deformities
delayed formation of teeth
defects in the structure of teeth, holes in the enamel
painful teeth, aching aggravated by sweets, or by cold/hot food or drinks
increased incidence of cavities in the teeth (dental caries)
fever, especially at night
restlessness, especially at night
weakness, progressive
decreased muscle tone (loss of muscle strength)
decreased muscle development
muscle cramps
impaired growth
short stature (adult is less than 5 feet tall)
growth, slow (child 0-5 years)
pectus excavatum
sutures - separated

Signs and Tests:
A musculoskeletal examination reveals tenderness or pain of the bone itself, rather than joints or muscles. In some cases, tetany (prolonged muscle spasm) may occur if serum levels of calcium are low. Chvostek's sign may be positive (a spasm of facial muscles with tapping over the facial nerve) indicating low serum levels of calcium.


Serum calcium and serum phosphorus may be low.
Serum alkaline phosphatase may be high.
Arterial blood gases may reveal metabolic acidosis.
Bone X-rays may show decalcification or changes in the shape/structure of the bones.
A bone biopsy is rarely performed but will confirm rickets.
Other tests and procedures to determine cause may be performed, such as:
a PTH
a calcium; urine
a calcium (ionized)
ALP (alkaline phosphatase) isoenzyme

Treatments:
The treatment goals are the relief of symptoms and the correction of the cause. The replacement of deficient calcium, phosphorous, and/or vitamin D causes symptoms to disappear. There may be a need to use the biologically active form of vitamin D in people who have vitamin D-resistant rickets or who have difficulty converting vitamin D to its active form. Dietary sources of vitamin D include fish, liver, and processed milk. Exposure to moderate amounts of sunlight is encouraged. The underlying cause must be treated to prevent recurrence. Maintaining good posture helps to correct skeletal deformities. Positioning or bracing may be used to reduce or prevent deformities. A surgical correction of some skeletal deformities may be necessary.

Complications:
chronic skeletal pain
skeletal deformities
skeletal fractures, may be spontaneous (without a cause such as trauma)

Call Healthcare Provider:
Call your health care provider if symptoms indicate rickets may be present.





2. Hypogonadotropic hypogonadism 
Absent or decreased gonadal function ( the male testis or the female ovary) resulting from the absence of the gonadal stimulating pituitary hormones FSH ( 3. Diabetes insipidus; nephrogenic 

A disorder characterized by pronounced thirst and the passage of large quantities of dilute urine, caused by a defect of the kidney tubules. See also diabetes insipidus; central
Hypogonadotropic hypogonadism 
Content Description:
Absent or decreased gonadal function ( the male testis or the female ovary) resulting from the absence of the gonadal stimulating pituitary hormones FSH (follicle stimulating hormone) and LH (luteinizing hormone).

Causes and Risk:
FSH and LH are hormones released by the pituitary gland. These hormones stimulate the ovaries (female) and testes (male) to secrete hormones that are responsible for normal development in puberty. Decreased levels of FSH and LH may occur in association with damage to or absence of the pituitary (hypopituitarism) gland or hypothalamus. In the absence of gonadal stimulation by FSH and LH puberty does not take place and the secondary sexual characteristics do not develop. 

Deficient FSH and LH (hypopituitarism) may also occur as a result of hypothalamic abnormalities. The hypothalamus produces the gonadotropin-releasing hormone (GnRH), which stimulates the pituitary to release FSH and LH. If gonadotrophin-releasing hormone is absent, the pituitary does not release FSH and LH and puberty does not take place.

Failure of the pituitary may result from empty sella syndrome, pituitary tumors (craniopharyngioma), head injuries, thalassemia major, or other causes. Kallmann's syndrome is a hereditary absence of the anterior pituitary and the inability to smell (anosmia). It is transmitted by eiher x-linked recessive (most common form) or autosomal dominant (least common form) inheritance. Kallmann syndrome is one of the more common causes of hypogonadotropic hypogonadism.

The following is a list of other conditions that may be associated with hypogonadotrophic hypogonadism:

Heritable and genetic disorders 
Kallmann syndrome 
Laurence-Moon-Biedl syndrome 
Prader-Willi syndrome 
Marinesco-Sjogren syndrome 
Infectious diseases 
tuberculosis 
HIV infection and AIDS 
Collagen vascular disease

Prevention:
Prevention is dependent on the cause. Genetic counseling may be appropriate for individuals with heritable disorders that are associated with hypogonadism. Prevention of serious head injuries reduces the risk of pituritary injury associated hypogonadotropic hypogonadism. 


Symptoms:
lack of development at puberty, incomplete development or significant delay of pubertal development 
prebubertal testicular size in adolescence 
absence of secondary sexual development 
short stature may be associated with some forms of hypogonadism 
anosmia (inability to smell) 

Signs and Tests:
gonadotropins and gonadal steroid serum levels 
GnRH stimulation test 
repeated measurements of FSH and LH levels (in females) 
blood chemistry, FSH levels 
MRI of the head 

Treatments:
(which treatment depends on the source of the defect) 

intramuscular (IM) testosterone 
human chorionic gonadotrophin (hCG) 
human menopausal gonadotrophin injections 
GnRH injections 

Complications:
delayed puberty 
infertility 
low self-esteem (Children who do not develop puberty changes until late may suffer from comparison with their peers. Lots of emotional support may be helpful.) 

Call your health care provider if your child does not enter puberty as expected. 



3.Diabetes insipidus; nephrogenic 
Content Description:
A disorder characterized by pronounced thirst and the passage of large quantities of dilute urine, caused by a defect of the kidney tubules. See also diabetes insipidus; central.

Causes and Risk:
Antidiuretic hormone (ADH; vasopressin) is a hormone produced in the hypothalamus of the brain. It concentrates the urine by triggering the kidneys to reabsorb water into the blood stream rather than excreting water into the urine.

Nephrogenic diabetes insipidus involves a defect in the kidney tubules (the portion of the kidneys that causes water to be excreted or reabsorbed). The kidney tubules lack the receptor for ADH that transmits the instruction to concentrate the urine to the inside of the cells. Excessive amounts of water are excreted with the urine, producing a large quantity of very dilute urine. There is no response to vasopressin, even though the blood level of this hormone is higher than normal.

If thirst mechanisms are normal and adequate fluids are consumed, there are no significant effects on the fluid and/or electrolyte balance of the body. If inadequate fluids are consumed, the high urine output may cause dehydration and high blood sodium.

Nephrogenic dI is a very rare disorder, affecting about 5 out of 100,000 people. It occurs primarily as a congenital, sex-linked disorder (congenital nephrogenic dI) that usually affects men, although women can pass the gene on to their children.

Nephrogenic diabetes insipidus may also be acquired (developed as a result of another disorder) in some people, especially those who have disorders of the renal medulla (such as amyloidosis), myeloma, malnutrition, analgesic nephropathy, decreased serum potassium levels, increased serum calcium levels, sickle cell anemia, and in women who are or who have recently been pregnant. It may be acquired by people who are taking medications including demeclocycline, lithium, and methicillin.

The primary risk factors include family history of congenital DI, and/or a history of medications or disorders associated with acquired nephrogenic dI.

Prevention:
There is no known prevention for congenital nephrogenic diabetes insipidus. Treatment of causative disorders may prevent some cases of acquired nephrogenic dI. Medications should only be used under the supervision of the health care provider.

Symptoms:
excessive thirst
may be intense or uncontrollable
craving for ice water may be present
excessive urine volume
may exceed 3 to 15 liters per day
Inadequate fluid consumption can result in:
dehydration
dry skin
dry mucous membranes
sunken appearance to eyes
sunken fontanelles (soft spot) in infants
fatigue, lethargy
headache
irritability
low body temperature
muscle pains
rapid heart rate
weight loss

Signs and Tests:
Examination may indicate dehydration and/or shock if fluid intake is inadequate. The pulse rate may be rapid with a low blood pressure present. The most significant indication of diabetes insipidus is persistent high urine output regardless of fluid intake.

Signs associated with high urine output are:
high serum osmolality
low urine osmolality
normal or high ADH levels
the kidneys not making a more concentrated urine when the person is given ADH
This disease may also alter the results of the following tests:
urine specific gravity
urine concentration test
urine 24h volume
serum sodium

Treatments:
The goal of treatment is to regulate fluid levels in the body.

All cases should be treated with consistently high fluid intake. The volume of fluids consumed should approximately equal the volume of urine produced.

Reduction or discontinuation of medications that may cause nephrogenic DI may improve symptoms.

Hydrochlorothiazide may improve symptoms. This may be used alone or in combination with other medications including indomethacin and (occasionally) desmopressin. Although this medication is a diuretic (these medications are usually used to increase urine output), hydrochlorothiazide can actually reduce the urine output for people with nephrogenic dI. This medication works by causing sodium and water to be excreted in the early part of the renal tubules (the proximal tubules). This leaves less fluid available for the late portion of the kidney to excrete (distal tubule)--this is the portion affected by nephrogenic DI--and thus it limits the total volume of urine that can be excreted.

Complications:
severe dehydration, shock (if inadequate fluid intake)
hypernatremia (high blood sodium)
dilation of the ureters and bladder

Call Healthcare Provider:
Call your health care provider if symptoms indicate diabetes insipidus may be present .






4. Glucose-6-phosphate dehydrogenase deficiency 

A hereditary, sex-linked, enzyme defect that results in the breakdown of red blood cells when the person is exposed to the stress of infection or certain drugs.

Glucose-6-phosphate dehydrogenase deficiency 
Content Description:
A hereditary, sex-linked, enzyme defect that results in the breakdown of red blood cells when the person is exposed to the stress of infection or certain drugs.

Causes and Risk:
G-6-PD deficiency is an inheritable x-linked recessive disorder whose primary effect is the reduction of G-6-PD in the red blood cell, with resultant hemolysis of the cell. The ultimate effect of the disease is to produce anemia, either acute hemolytic or a chronic spherocytic type.

In the United States, the incidence of G-6-PD is much higher among the Black American population with a heterozygote frequency (carrier state with one normal gene and one abnormal gene) of 24%. Approximately 10 to 14% of the black American male population is affected. The disorder may occasionally affect a few black females to a mild degree (depending on their genetic inheritance). People with the disorder are not normally anemic and display no evidence of the disease until the red cells are exposed to an oxidant or stress.

Drugs that can precipitate this reaction include:

  antimalarial agents
  sulfonamides (antibiotic)
  aspirin
  nonsteroidal antiinflammatory drugs (NSAIDs)
  nitrofurantoin
  quinidine
  quinine
  Also:
  exposure to certain chemicals such as those in mothballs
  The chronic spherocytic anemia is unaffected by exposure 
  to these drugs.

The risk of acute hemolytic crisis can be decreased by reviewing the family history for any evidence of hemolytic anemias or spherocytosis or testing before giving any medications belonging to the above class of chemicals.

The episodes are usually brief, because newly produced (young) red cells have normal G6PD activity.

Risk factors are being of the black race, being male, or having a family history of G6PD deficiency. Another type of this disorder can occur in whites who originated in the Mediterranean basin. It, too, is associated with acute episodes of hemolysis. Episodes are longer and more severe than the other type of disorders.

Prevention:
People with G-6-PD must strictly avoid factors that can precipitate an episode, especially drugs known to cause oxidative reactions.

Genetic counseling or genetic information may be of interest to heterozygous women and affected men.

Symptoms:
fatigue
pale color
shortness of breath
rapid heart rate
yellow skin color (jaundice)
dark urine
enlarged spleen
Note: Severe hemolysis may cause hemoglobinuria.

Signs and Tests:
anemia
hemolysis
reduced G-6-PD activity
reticulocytosis following a hemolytic crisis
Tests include:
elevated bilirubin levels
low serum haptoglobin
hemoglobin in the urine
elevated absolute reticulocyte count
low red blood cell count and hemoglobin
Heinz bodies present on examination of the peripheral blood smear using special stains
methylene blue test
methemoglobin reduction test

Treatments:
If the cause is an infection, it should be treated, or if the cause is a drug, the offending agent should be stopped. People with the Mediterranean form or those in hemolytic crisis may occasionally require transfusions.

Complications:
Rarely, death may occur following a severe hemolytic event.

Call Healthcare Provider:
Call for an appointment with your health care provider if symptoms of hemolytic anemia due to G6PD deficiency develop.

Call your health care provider if you have G6PD deficiency and symptoms of hemolytic anemia do not disappear after treatment of the cause.





5. Hemophilia 
A sex-linked hereditary bleeding disorder in which it takes a long time for the blood to clot and abnormal bleeding occurs. This disease affects mostly males. Diseases in this category include:


6. Hemophilia A 
A hereditary blood coagulation disorder caused by a deficient activity of plasma protein factor VIII, which affects the clotting property of blood.


7. Hemophilia B 
A hereditary blood coagulation disorder caused by a deficiency of a plasma protein called factor IX that affects the clotting property of blood.


8. Endometriosis 
A condition in which the tissue that normally lines the uterus (endometrium) grows in other areas of the body, causing pain, irregular bleeding, and frequently infertility. The 
Endometriosis 
Content Description:
A condition in which the tissue that normally lines the uterus (endometrium) grows in other areas of the body, causing pain, irregular bleeding, and frequently infertility. The tissue growth typically occurs in the pelvic area, outside of the uterus, on the ovaries, bowel, rectum, bladder, and the delicate lining of the pelvis, but it can occur in other areas of the body.

Causes and Risk:
The cause of endometriosis is unknown; however, a number of theories have been proposed. The retrograde-menstruation theory proposes that endometrial cells (loosened during menstruation) may "back up" through the fallopian tubes into the pelvis, where they implant and grow in the pelvic and/or abdominal cavities. The immune-system theory suggests that a deficiency in the immune system allows menstrual tissue to implant and grow in areas other than the uterine lining. Another theory suggests that the cells lining the abdominal cavity may spontaneously develop endometriosis. A genetic theory proposes that certain families may exhibit predisposing factors that lead to endometriosis. 

Once the endometrial cells implant in tissue outside of the uterus they become a problem. Each month the ovaries produce hormones that stimulate the cells of the uterine lining to multiply and prepare for a fertilized egg (swell and thicken). The endometrial cells outside of the uterus also respond to this signal, but they lack the ability to separate themselves from the tissue and slough off during the next menstrual period. They sometimes bleed a little bit but they heal and are stimulated again during the next cycle. This ongoing process causes scarring and adhesions in the tubes and ovaries, and around the tubal fimbriae (fingerlike projections at the end of the fallopian tubes). These adhesions can make transfer of an ovum from the ovary to the fallopian tube difficult or impossible. They can also stop passage of a fertilized egg down the fallopian tube to the uterus. 

Once in a while the growing cells will penetrate the tough covering of the ovary and begin to multiply. These cells can collect large amounts of blood and form what is called, appropriately, an ovarian blood cyst (endometrioma). These have been known to grow to the size of a hen's egg or even an orange, and are usually very painful. Over time the collected blood darkens and for this reason the cysts are frequently called "chocolate cysts." 

Endometriosis is a common problem among women and occurs in an estimated 10% to 20% of them during their reproductive years. The prevalence may be as high as 15% to 40% among infertile women. Although endometriosis is typically diagnosed between the ages of 25 and 35, the problem probably begins about the time that regular menstruation begins. Adolescents may experience symptoms such as severe cramping or discomfort, but these symptoms are frequently ignored or written off as normal. A woman who has a mother or sister with endometriosis has a risk of developing endometriosis that is 6 times greater than that of the general population. Other risk factors include having menstrual cycle lengths of 27 days or less, early onset of menstrual periods, and periods lasting 7 or more days. Orgasm during the menstrual cycle has also been noted as a potential risk factor (linked to the retrograde menstruation theory). 


Prevention:
There is no proven prevention for endometriosis. However, some women with endometriosis who successfully become pregnant find that they are free of the disease afterwards. Pregnancy also tends to delay the onset and progression of the disease in susceptible women. 


Symptoms:
onset of increasingly painful periods 
steady dull-to-severe lower abdominal pain that can be felt just before or during menstruation, or for a week or two preceding it 
pelvic or low back pain that may occur at any time during the menstrual cycle 
typically, severe pelvic cramps or abdominal pain that may start 1 to 2 weeks before the menstrual period 
more frequent or totally irregular periods 
premenstrual spotting 
pain during or following sexual intercourse 
pain with bowel movements 
infertility 
Note: Frequently, symptoms may not be present. In fact, some women with severe cases of endometriosis have no pain at all, while some women with only a few small adhesions have severe discomfort. 


Signs and Tests:
A pelvic examination may reveal the presence of tender nodules, with a lumpy consistency. These are often found in the posterior vaginal wall or adnexa (ovary regions) and may sometimes be felt in healed wound scars (especially those from episiotomy and C-section). There may be pain with uterine motion. The uterus may be fixed or retroverted. 

a laparoscopy is necessary for diagnosis 
an exploratory laparotomy is rarely necessary

Treatments:
Treatment depends on the extent of the disease (determined through laparoscopy); the woman's desire for future childbearing; the degree of symptoms experienced; and the woman's age. 

Observation may be the appropriate treatment for younger women with minimal disease and symptoms. It is important to have the woman maintain a regular schedule of examinations (every 6 to 12 months) to note any changes or progression of the disease. 

Treatment with medications may focus on several strategies: Analgesic therapy, treating the discomfort of the disease only, may be indicated for women with mild to moderate premenstrual pain, with no pelvic examination abnormalities, and with no immediate desire to become pregnant.

"Pseudopregnancy" (a state resembling pregnancy) may be achieved through hormonal drug regimens. This approach was developed in response to the observed regression of endometriosis during pregnancy. Pseudopregnancy can be induced using oral contraceptives containing estrogen and progesterone. This takes six to nine months and relieves most of the symptoms, but does not prevent scarring and adhesion left by the disease. Potential side effects of depression and/or significant breakthrough spotting may limit this option for treatment. 

Similarly, "pseudomenopause" (a state resembling menopause) was developed as a means of treatment because of the observation that endometriosis regresses after menopause. Danazol, a weak androgenic (male characteristic) hormonal drug may be used to reduce natural levels of estrogen and progesterone to low levels. It appears that the use of danazol may be superior to the "pseudopregnancy" regimens in controlling symptoms and progression of the disease in women with moderate-to-severe endometriosis. However, in cases of mild disease, danazol may prove to be much more expensive and no more effective than simple observation. 

A new class of antigonadotropin drugs has been developed that also produces a "pseudomenopausal" state in women. Both Synarel and Depolupron (trade names) prevent stimulation of the pituitary for the production of FSH (follicle stimulating hormone) and LH (luteinizing hormone). This stops the ovary from producing estrogen. Potential side effects of these drugs include menopausal symptoms such as hot flashes, vaginal dryness, mood changes, and early loss of calcium from the bones. 

Surgery is usually reserved for women with severe endometriosis, including adhesions and infertility. Conservative surgery attempts to remove or destroy all of the outside endometriotic tissue, remove adhesions, and restore the pelvic anatomy to as close to normal as possible. Nerve removal (neurectomy) may be performed during surgery as a means of relieving the pain associated with endometriosis. 

Definitive surgery is appropriate for the woman with severe symptoms or disease, and no desire for future childbearing. This type of surgery involves abdominal removal of the uterus, both ovaries, both fallopian tubes, and any remaining adhesions or endometriotic implants. Hormonal replacement therapy may be indicated after total hysterectomy and should be tailored to the individual woman's needs. 


Complications:
Infertility may result from endometriosis. Therefore, if a woman desires to have children and knows she has the disease, it may be recommended that she plan to have her children earlier and with shorter time spans in between children. Endometriosis has been known to recur even after a hysterectomy. Other complications are rare. In a few cases endometriosis implants may cause obstructions of the gastrointestinal or urinary tracts. 



Call for an appointment with your health care provider if symptoms of endometriosis occur, or if back pain or other symptoms recur after treatment of endometriosis. 

Screening for endometriosis should be considered if your mother or sister has been diagnosed with endometriosis, or if you are unable to become pregnant after 1 year of attempting to conceive. 


9. Muscular dystrophy 
Muscular dystrophy 
Content Description:

A group of disorders characterized by progressive muscle weakness and loss of muscle tissue.

Causes and Risk:
The group of diseases called muscular dystrophies includes many inherited disorders such as: 

Becker's muscular dystrophy 
Duchenne's muscular dystrophy 
facioscapulohumeral muscular dystrophy 
limb-girdle muscular dystrophy 
Emery-Dreifuss muscular dystrophy
myotonic dystrophy
myotonia congenita
Disorders are distinguished by the type of inheritance ( sex-linked, dominant genes , or recessive gene, and so on), the age when symptoms appear, and the types of symptoms that develop. Because these are inherited disorders, risks include a family history of muscular dystrophy. 

Lambert-Eaton syndrome and myasthenia gravis have symptoms that may be similar to early stages of some types of muscular dystrophies.

Prevention:
Genetic counseling is advised when there is a family history of 
muscular dystrophy. Women may be asymptomatic but still be carriers of the gene for the disorder. Duchenne's muscular dystrophy can be detected with about 95 percent accuracy by genetic studies performed during pregnancy.

Symptoms:
Symptoms vary with the different types of muscular dystrophy. Certain types, such as Duchenne dystrophy, are ultimately fatal while other types have associated muscle weakness but cause little disability.

muscle weakness 
progressive 
frequent falls 
delayed development of muscle skills 
problems walking 
difficulty using a muscle group (the specific muscle affected depends on the type of MD) 
eyelid drooping (ptosis) 
drooling 
intellectual retardation 
only present in some types of MD 
hypotonia 
skeletal deformities 
muscle deformities 
contracture deformities (clawfoot, clawhand or others)
scoliosis
enlargement of the calve muscles (pseudohypertrophy)

Signs and Tests:
Examination and history help to distinguish the type of MD. Specific muscle groups are affected by different types of MD. Often, there is a loss of muscle mass (wasting), which may be disguised in some types of muscular dystrophy by an accumulation of fat and connective tissue making the muscle appear larger (pseudohypertrophy). Muscle contractures are common. Shortening of the muscle fibers, fibrosis of the connective tissue and scarring slowly destroy muscle function. Some types of MD involve the heart muscle, causing cardiomyopathy or arrhythmias. 

A muscle biopsy is the primary test used to confirm the diagnosis. 
A serum CPK may be elevated. 
An EMG (electromyography) may confirm that weakness is caused by destruction of muscle tissue rather than damage to nerves. 
An ECG (electrocardiography) to monotor changes in cardiac status
This disease may also alter the results of the following tests: 
myoglobin - urine 
myoglobin - serum 
LDH isoenzymes 
LDH 
creatinine - urine 
creatinine 
CPK isoenzymes 
AST 
aldolase 

Treatments:
There is no known cures for the various muscular dystrophies. Treatment is aimed at controlling symptoms to maximize the quality of life. Activity is encouraged to the degree tolerated. Inactivity (such as bedrest) can worsen the muscle disease. Physical therapy may be helpful to maintain muscle strength and functioning. Orthopedic appliances such as braces and wheelchairs may improve mobility and self-care abilities. 

The stress of illness can often be helped by joining support groups where members share common experiences and problems. See muscular dystrophy - support group.

Complications:
deformities 
permanent, progressive disability 
decreased mobility 
decreased ability to care for self 
mental impairment (varies) 
cardiomyopathy 
respiratory failure (can cause death) 

Call Healthcare Provider:
Call your health care provider if the symptoms indicate muscular dystrophy may be present. 

Call for an appointment with your health care provider if there is a personal or family history of muscular dystrophy and children are planned.


A group of disorders characterized by progressive muscle weakness and loss of muscle tissue.


10. Chronic granulomatous disease 
An inherited abnormality of certain cells of the immune system that "ingest" bacteria and kill them (phagocytic cells); the abnormality results in chronic infection by certain types of bacteria.

 


matching "sex linked disease"
1. Rickets 
A disorder involving softening and weakening of the bones of children, primarily caused by lack of vitamin D and/or lack of calcium or phosphate.

2. Hypogonadotropic hypogonadism 
Absent or decreased gonadal function ( the male testis or the female ovary) resulting from the absence of the gonadal stimulating pituitary hormones FSH ( 

3. Diabetes insipidus; nephrogenic 
A disorder characterized by pronounced thirst and the passage of large quantities of dilute urine, caused by a defect of the kidney tubules. See also diabetes insipidus; central


4. Glucose-6-phosphate dehydrogenase deficiency 
A hereditary, sex-linked, enzyme defect that results in the breakdown of red blood cells when the person is exposed to the stress of infection or certain drugs.


5. Hemophilia 
A sex-linked hereditary bleeding disorder in which it takes a long time for the blood to clot and abnormal bleeding occurs. This disease affects mostly males. Diseases in this category include:

6. Hemophilia A 
A hereditary blood coagulation disorder caused by a deficient activity of plasma protein factor VIII, which affects the clotting property of blood.


7. Hemophilia B 
A hereditary blood coagulation disorder caused by a deficiency of a plasma protein called factor IX that affects the clotting property of blood.


8. Endometriosis 
A condition in which the tissue that normally lines the uterus (endometrium) grows in other areas of the body, causing pain, irregular bleeding, and frequently infertility. The 


9. Muscular dystrophy 
A group of disorders characterized by progressive muscle weakness and loss of muscle tissue.


10. Chronic granulomatous disease 
An inherited abnormality of certain cells of the immune system that "ingest" bacteria and kill them (phagocytic cells); the abnormality results in chronic infection by certain types of bacteria.


11. Scrotal masses 
       A scrotal mass is a lump or bulge that can be felt in the scrotum.
12. Developmental disorders of the vagina and vulva 
       A variety of structural abnormalities that occur during fetal development.
13. Genetics 
14. Autosomal dominant 
15. SEX-LINKED DOMINANT 
16. SEX-LINKED RECESSIVE 
17. Autosomal recessive 
18. Genetic counseling and prenatal diagnosis 
19. Chromosome 
20. Gene 



 

 


 






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