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- $Unique_ID{BRK03568}
- $Pretitle{}
- $Title{Carnosinemia}
- $Subject{Carnosinemia Carnosinase Deficiency Hyper-Beta Carnosinemia
- Phenylketonuria (PKU)}
- $Volume{}
- $Log{}
-
- Copyright (C) 1986, 1987, 1989 National Organization for Rare Disorders,
- Inc.
-
- 162:
- Carnosinemia
-
- ** IMPORTANT **
- It is possible that the main title of the article (Carnosinemia) is not
- the name you expected. Please check the SYNONYM listing to find the
- alternate names and disorder subdivisions covered by this article.
-
- Synonyms
-
- Carnosinase Deficiency
- Hyper-Beta Carnosinemia
-
- Information on the following diseases can be found in the Related
- Disorders section of this report:
-
- Phenylketonuria (PKU)
-
- General Discussion
-
- ** REMINDER **
- The information contained in the Rare Disease Database is provided for
- educational purposes only. It should not be used for diagnostic or treatment
- purposes. If you wish to obtain more information about this disorder, please
- contact your personal physician and/or the agencies listed in the "Resources"
- section of this report.
-
-
- Carnosinemia is a hereditary metabolic disorder characterized by severe
- mental retardation and convulsive muscular contractions.
-
- Symptoms
-
- In carnosinemia, the first episodes of twitching occur in the second or third
- month of life. Growth, motor and intellectual development is slow. The skin
- may turn bluish due to a deficiency of oxygen in the blood (cyanosis). As
- damage to the nervous system progresses, sudden muscle jerks involve the head
- and limbs. Sleepy and lethargic periods may be followed by convulsions and
- seizures. By the age of two years, the child may be mentally retarded.
-
- Causes
-
- Carnosinemia is an autosomal recessive hereditary metabolic disorder. (Human
- traits, including the classic genetic diseases, are the product of the
- interaction of two genes, one received from the father and one from the
- mother. In recessive disorders, the condition does not appear unless a
- person inherits the same defective gene for the same trait from each parent.
- If one receives one normal gene and one gene for the disease, the person will
- be a carrier for the disease, but usually will show no symptoms. The risk of
- transmitting the disease to the children of a couple, both of whom are
- carriers for a recessive disorder, is twenty-five percent. Fifty percent of
- their children will be carriers, but healthy as described above. Twenty-five
- percent of their children will receive both normal genes, one from each
- parent, and will be genetically normal.)
-
- The biochemical defect involved in carnosinemia is not fully understood.
- It is known that the enzyme carnosinase does not function properly in its
- role of breaking down carnosine, a dipeptide usually occurring in the
- muscles. In patients with this disorder, there is evidence of little or no
- carnosinase activity in the blood, and carnosine is usually found in the
- urine.
-
- Affected Population
-
- Carnosinemia is a very rare disorder that affects males and females in equal
- numbers.
-
- Related Disorders
-
- Symptoms of the following disorders can be similar to those of carnosinemia.
- Comparisons may be useful for a differential diagnosis:
-
- Phenylketonuria (PKU) is an inherited metabolic disease which, if
- untreated, can lead to severe mental retardation. Children having PKU are
- often irritable, restless and destructive, and may have a musty odor, dry
- skin or rashes. (For more information on this disorder, choose "PKU" as your
- search term in the Rare Disease Database).
-
- Therapies: Standard
-
- Treatment of carnosinemia is symptomatic and supportive. Low carnosine diets
- are being evaluated in the treatment of carnosinemia as is intravenous
- replacement of carnosinase. More research is necessary to determine if these
- treatments will be safe and effective.
-
- Therapies: Investigational
-
- This disease entry is based upon medical information available through June
- 1989. Since NORD's resources are limited, it is not possible to keep every
- entry in the Rare Disease Database completely current and accurate. Please
- check with the agencies listed in the Resources section for the most current
- information about this disorder.
-
- Resources
-
- For more information on Carnosinemia, please contact:
-
- National Organization for Rare Disorders (NORD)
- P.O. Box 8923
- New Fairfield, CT 06812-1783
- (203) 746-5248
-
- National Digestive Diseases Information Clearinghouse
- P.O. Box NDDIC
- Bethesda, MD 20892
- (301) 468-6344
-
- Research Trust for Metabolic Diseases in Children
- Golden Gates Lodge, Weston Rd.
- Crewe CW1 1XN, England
- Telephone: (0270) 250244
-
- For genetic information and genetic counseling referrals, please contact:
-
- March of Dimes Birth Defects Foundation
- 1275 Mamaroneck Avenue
- White Plains, NY 10605
- (914) 428-7100
-
- Alliance of Genetic Support Groups
- 35 Wisconsin Circle, Suite 440
- Chevy Chase, MD 20815
- (800) 336-GENE
- (301) 652-5553
-
- References
-
- MENDELIAN INHERITANCE IN MAN, 8th ed.: Victor McKusick; John Hopkins
- University Press, 1986. Pp. 850.
-
- THE METABOLIC BASIS OF INHERITED DISEASE, 5th Ed.: John B. Stanbury, et
- al., eds.; McGraw Hill, 1983. Pp. 571, 580.
-
-