Identification of three novel mutations

Maple Syrup Urine Disease (MSUD) is a genetically heterogeneous metabolic disorder that is transmitted in an autosomal recessive manner. According to clinical data MSUD prevalence in Lebanon is expected to be higher than the International prevalence because of consanguineous marriage. Novel mutations are still getting detected by using DNA sequencing for mutation analysis in MSUD patients. In the current study we have extracted DNA from Lebanese MSUD patients in order to amplify the exonic and flanking intronic regions of the genes implicated in MSUD (BCKDHA BCKDHB and DBT) and sequenced the resultant amplified products to assess the molecular genetics of MSUD in the Lebanese population studied. All of the mutations identified occurred in the homozygous state which reflects the high rate of consanguineous marriage in Lebanon. In the current study we have identified one previously cited mutation and three novel mutations not previously described in the scientific literature. The majority of the mutations identified in the Lebanese MSUD patients occurred in the DBT gene. Consanguineous marriage is a major risk factor for the prevalence of MSUD in Lebanon.