Genetic diseases disorders

Another class of therapeutic agents is used for the treatment of certain genetic diseases or other enzymatic disorders caused by the dysfunction or absence of one particular enzyme. This often leads to an unwanted accumulation or imbalance of metaboUtes in the organism. Eor example, some anticonvulsive agents are inhibitors for y-aminobutyric acid aminotransferase [9037-67-6]. An imbalance of two neurotransmitters, glutamate and y-aminobutyric acid, is responsible for the symptoms. Inhibition of the enzyme leads to an increase of its substrate y-aminobutyric acid, decreasing the imbalance and subsequently relieving the symptoms of the disease. 

The biosynthesis of purines and pyrimidines is stringently regulated and coordinated by feedback mechanisms that ensure their production in quantities and at times appropriate to varying physiologic demand. Genetic diseases of purine metabolism include gout, Lesch-Nyhan syndrome, adenosine deaminase deficiency, and purine nucleoside phosphorylase deficiency. By contrast, apart from the orotic acidurias, there are few clinically significant disorders of pyrimidine catabolism. 

Is to determine the sex of the fetus the other Is to determine whether the fetus has a chromosome abnormality Fetal sex determination Is not, at present, performed so that couples can chose the sex of their baby While there may not be any significant ethical or sociological (43) reasons to oppose sex determination for this reason, the lack of sufficient facilities has made this an Indication of extremely low priority The reason for ascertaining the sex of a fetus. In so far as the prenatal diagnosis of genetic disease Is concerned. Is to determine Aether the fetus Is a male or female In situations In which the parents are at risk of having a child with an X-llnked disorder which affects only males If the fetus Is a male. It will have a 50% risk of being affected This risk. In such... 

Summary Thalassemias as a group are the most common genetic diseases in the world. Beta thalassemia is an inherited blood disorder in which the body produces an abnormal form of hemoglobin. The disorder results in excessive destruction of red blood cells, which in a severe form manifests as life-shortening anemia shortly after birth. Short-chain fatty acids had previously been shown to be useful in the... 

Although chelation is not helpful for Alzheimer s disease patients, it is the key to treating patients with dementia due to Wilson s disease. Wilson s disease is a genetically inherited disorder that usually strikes before age 30. The disease causes toxic levels of copper to accumulate in the liver, brain, eyes, and kidney. Untreated, Wilson s disease leads to tremors, cirrhosis, depression, psychosis, dementia, and ultimately death. Chelation with penicillamine (Cuprimine) can stop and even reverse the accumulation of copper. 

Examp 1 es of genetic diseases that show anticipation are Huntington disease, Fragile X syndrome, and other disorders that arise from trinucleotide repeat... 

As discussed above, in the case of phenylketonuria, early intervention can make the difference between mental retardation and a near normal life course for a newborn. Congenital adrenal hyperplasia and maple syrup urine disease are two examples of neonatal hereditary disorders where early diagnosis and medical intervention can make the difference between life and death for the newborn. In addition, in a number of genetic diseases, early diagnosis and treatment can help ameliorate symptoms these include fragile X syndrome, homocystinuria, sickle cell anemia, cystic fibrosis, and many /1-thalassemias. 

Bayesian probabilities are absolutely reliant upon an accurate family history of the disease in question. Family history affects the prior or a priori likelihood that a propositus is a carrier for a genetic disease. Because many hereditary disorders are autosomal recessives and manifest rarely in a sibship, any record of a known hereditary disorder can be important in providing an accurate risk reduction. This can be particularly important in cystic fibrosis, where one of the mutations is often known in affected individuals while the other is often private and uncharacterized. Fven an affected first cousin can boost the a priori probability in a Caucasian non-Jew from 1/241 to 1/8. 

Gleeson, J.G., and Walsh, C.A. (2000) Neuronal migration disorders from genetic diseases to developmental mechanisms. Trends Neurosci 23 352-359. 

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