الفهرس 
Inherited metabolic disordersOnly 14 pages are availabe for public view
Abstract
Maple syrup urine disease is a rare hereditary disease affects newly born children causes accumulative effects on CNS, the symptoms starts to appear from second day of birth in the form of poor feeding with recurrent vomiting, irritability, lethargy, abnormal consciousness sand convulsions these disorders can cause irreversible mental retardation (ranging from mild to severe) and if untreated rapidly it may causes death.
A former Egyptian study reported that 51 cases out 450 studied (11.3%) of mental retarded cases have confirmed positive inborn errors of amino acid metabolism.
The newborn screening programs allowed early diagnosis of classic MSUD and initiation of dietary therapy, which is essential to avoid irreversible neurological damage and death, and to optimize the outcome of MSUD patients by close follow-up.
The disease was firstly described at 1954, although it was a rare disease (1/180,000) but it spreads in all races as a result of recessive mutation causes failure of branched chain amimo acids catabolism (leucine, isoleucine and valine) leads to accumulation of intermediate products to represent these amino acids and cause the emergence of neurological symptoms mentioned above.The disease was divided according to the severity of the emergence of clinical symptoms into 5 groups.
Studies have shown that the genetic recessive gene mutation occurs specifically in 3 specific genes (E1ά, E1ß, E2), although most mutations occur in the E1ά gene specifically.
In this study, we focused on mutations that occur in chromosome 19, specifically the E1 ά gene (because it is one of the most common mutations), so that this gene is detected in early screening programs for newborns, resulting in reduced mortality rates for children with the disease.
The study included 6 children who were diagnosed with the disease randomly selected from patients who were in the Pediatric Unit at Ain Shams University and a control group of 10 healthy children, the following genetic tests were carried out:
1. Isolation, separation and purification of DNA
2. Conduct the PCR analysis of the mutation gene
3 - Cutting the specific part of the gene on the disease from the DNA double stranded DNA and replicate it to be examined with / or rearrangement of the specific part of the gene for the disease after multiplying it to determine the type of genetic mutation in the Arab Republic of Egypt of the disease.
The results were:1. The discovery of a novel mutation of the disease in one of the patients studied in chromosome No. 19 in exon 5, which resulted in the deletion of base 512 that changed the structure of the resulting protein to become a protein with only 170 amino acid (instead of 445 amino acid), which negatively affected its performance and function .
2 - Discovery of a second novel mutation of the disease in one of the patients studied in chromosome No. 19 exon 7, where the deletion of 10 consecutive bases starting from the base No. 947 to base No. 956, which led to change the structure of the resulting protein to become a protein only 120 amino acid (instead of 445 amino acid), which adversely affected the performance and function and cause the disease.
3 - Determination of a mutation of the disease (previously discovered in 1994) of the disease in one of the patients studied in chromosome No. 19 exon 7, where 8 consecutive bases were deleted from the base No. 859 to base No. 866, which led to the structure of the resulting protein to become a protein with 198 Amino acid only (instead of 445 amine), which negatively affected its performance and function and caused the disease.
4 - Determination of a mutation of the disease (previously discovered in 1989) of the disease in three of the patients studied (and do not have any close relationship) in chromosome No. 19 exon7 where the replacement of base No.1312 with a different base, which led to change the structure of the resulting protein to a protein lacking 159 amino acid from its natural counterpart, which adversely affected its performance and function and cause the disease.
Detection of the mutations found in Maple syrup urine disease patients will contribute to the confirmation of the diagnosis of the disease which is important in determining the appropriate treatment before it causes permanent damage to the brain and nervous system or perhaps the death. It also helps in the early diagnosis of disease in families with a history associated with the disease.