Аутистичен спектър. Аутизъм - тема 10

Изследвахме детето за нивото на амоняка в кръвта в селската болница - аз живея
в едно село в Америка,
идеята да го тествам за амоняк беше моя - вдъхнових се от историята на
Денис какво точно да изследвам. Резултата от изследванията
ги знам само от десетина дена, през това време
успях да се запиша за час при гастроентеролог, от който
не очаквам чудеса, а по-скоро позволение да ме прати до
лабораторията да направя няколко теста - Organic Acid Test за кандида и др. гадини
и  Amino acid profile - май брои количеството на всяка амино киселина.
От гастроентеролога очаквам да ми 'позволи' да започна
извличане на амоняка от кръвта с Citrudex.
Става въпрос за дете на две години.

Говоря ти за хиперамонемия, която може да се дължи на урея цикъл дефект с различна степен,
като например има И ПО-НЕЖНИ ФОРМИ НА ТОЗИ ДЕФЕКТ, които не водят до смърт,
а до различни форми на умствено изоставане
или до изоставане в речта и до неврологични проблеми,
а също така при деца води до хиперактивност.

Хиперамонемията може да бъде предизвикана, както от урея цикъл дефект,
така и от прекалено голям прием на протеини в диетата
или от вирусни заболявания като разни форми на шарка например.
Ето ти малко на английски от уйкипедия:

http://en.wikipedia.org/wiki/Urea_cycle_disorder


The neonatal period
Children with very severe urea cycle disorders typically show symptoms after the first 24 hours of life. The baby may be irritable at first, followed by vomiting and increasing lethargy. Soon after, seizures, hypotonia (poor muscle tone), respiratory distress, and coma may occur. If untreated, the child will die. These symptoms are caused by rising ammonia levels in the blood. Acute neonatal symptoms are most frequently seen in, but not limited to, boys with OTC Deficiency.


[edit] Childhood
Children with mild or moderate urea cycle enzyme deficiencies may not show symptoms until early childhood, or may be diagnosed subsequent to identification of the disorder in a more severely affected relative or through newborn screening. Early symptoms may include hyperactive behavior, sometimes accompanied by screaming and self-injurious behavior, and refusal to eat meat or other high-protein foods. Later symptoms may include frequent episodes of vomiting, especially following high-protein meals; lethargy and delirium; and finally, if the condition is undiagnosed and untreated, coma and death. Children with this disorder may be referred to child psychologists because of their behavior and eating problems. Childhood episodes of hyperammonemia (high ammonia levels in the blood) may be brought on by viral illnesses including chicken pox, high-protein meals, or even exhaustion. The condition is sometimes misdiagnosed as Reye’s Syndrome. Childhood onset can be seen in both boys and girls.


[edit] Adulthood
Recently, the number of adult individuals being diagnosed with urea cycle disorders has increased at an alarming rate. Recent evidence has indicated that these individuals have survived undiagnosed to adulthood, probably due to less severe enzyme deficiencies. These individuals exhibit stroke-like symptoms, episodes of lethargy, and delirium. These adults are likely to be referred to neurologists or psychiatrists because of their psychiatric symptoms. However, without proper diagnosis and treatment, these individuals are at risk for permanent brain damage, coma, and death. Adult-onset symptoms have been observed following viral illnesses, childbirth, and use of valproic acid (an anti-epileptic drug).


[edit] The six urea cycle disorders
There are six disorders of the urea cycle. Each is referred to by the initials of the missing enzyme.

Location Abb. Enyzme Disorder Measurements
Mitochondria NAGS N-Acetylglutamate synthetase N-Acetylglutamate synthase deficiency +Ammonia
Mitochondria CPS1 Carbamoyl phosphate synthetase I Carbamoyl phosphate synthetase I deficiency +Ammonia
Mitochondria OTC Ornithine transcarbamylase Ornithine transcarbamylase deficiency +Ornithine, +Uracil, +Orotic acid
Cytosol AS Argininosuccinic acid synthetase "AS deficiency" or citrullinemia +Citrulline
Cytosol AL Argininosuccinase acid lyase "AL deficiency" or argininosuccinic aciduria (ASA) +Citrulline, +Argininosuccinic acid
Cytosol AG Arginase "Arginase deficiency" or argininemia +Arginine

Individuals with childhood or adult onset disease may have a partial enzyme deficiency. All of these disorders are transmitted genetically as autosomal recessive genes - each parent contributes a defective gene to the child, except for one of the defects, Ornithine Transcarbamylase Deficiency. This urea cycle disorder is acquired in one of three ways: as an X-linked trait from the mother, who may be an undiagnosed carrier; in some cases of female children, the disorder can also be inherited from the father's X-chromosome; and finally, OTC deficiency may be acquired as a "new" mutation occurring in the fetus uniquely. Recent research has shown that some female carriers of the disease may become symptomatic with the disorder later in life, suffering high ammonia levels. Several undiagnosed women have died during childbirth as a result of high ammonia levels and on autopsy were determined to have been unknown carriers of the disorder.

Treatment
The treatment of urea cycle disorders consists of balancing dietary protein intake in order that the body receive the essential amino acids responsible for cell growth and development, but not so much protein that excessive ammonia is formed. This protein restriction is used in conjunction with medications which provide alternative pathways for the removal of ammonia from the blood. These medications are usually given by way of tube feedings, either via gastrostomy tube (a tube surgically implanted in the stomach) or nasogastric tube through the nose into the stomach. The treatment may also include supplementation with special amino acid formulas developed specifically for urea cycle disorders, multiple vitamins and calcium supplements. Frequent blood tests are required to monitor the disorders and optimize treatment, and frequently hospitalizations are necessary to control the disorder.
Since the disease results in an inability to handle large amounts of nitrogen load, the treatment includes strategies to decrease the intake of nitrogen (low-protein diet), prevention of excessive body protein breakdown during acute illnesses (hydration and nutrition) and administration of medications scavenging nitrogen (sodium benzoate and sodium phenylbutyrate). Some patients may need to have supplemental amino acids (arginine, citrulline, valine, leucine, isoleucine).
In cases where the OTC enzyme production is very low or non-existent and treatment consisting of low-protein diet and dietary supplementation are inadequate, liver transplant may become a treatment option.
At the most extreme end of the spectrum, a few liver transplants have been done successfully as a cure to the disorder. This treatment alternative must be carefully evaluated with medical professionals to determine if potential of success as compared to the potential for new medical concerns.