Identification of three novel mutations by studying the molecular genetics of Maple Syrup Urine Disease (MSUD) in the...

Area of Science:

• Genetics
• Metabolic Disorders
• Molecular Biology

Background:

• Maple Syrup Urine Disease (MSUD) is an autosomal recessive metabolic disorder.
• Consanguineous marriage in Lebanon may contribute to a higher prevalence of MSUD than internationally observed.
• Ongoing research seeks to identify novel mutations in MSUD patients through DNA sequencing.

Purpose of the Study:

• To investigate the molecular genetics of MSUD in the Lebanese population.
• To identify mutations in the BCKDHA, BCKDHB, and DBT genes in Lebanese MSUD patients.
• To assess the role of consanguineous marriage in the prevalence of MSUD in Lebanon.

Main Methods:

• DNA was extracted from Lebanese MSUD patients.
• Exonic and flanking intronic regions of MSUD-implicated genes (BCKDHA, BCKDHB, DBT) were amplified.
• Amplified DNA products were sequenced for mutation analysis.

Main Results:

• One previously reported mutation and three novel mutations were identified in Lebanese MSUD patients.
• All identified mutations were in a homozygous state, consistent with high consanguinity rates.
• Mutations were distributed as follows: DBT gene (60%), BCKDHA gene (20%), and BCKDHB gene (20%).
• The majority of identified mutations occurred in the DBT gene.

Conclusions:

• The genetic basis of MSUD in the studied Lebanese population involves mutations in BCKDHA, BCKDHB, and DBT genes.
• Consanguineous marriage is a significant risk factor contributing to the prevalence of MSUD in Lebanon.
• Novel mutations in MSUD patients continue to be discovered, expanding the known mutational spectrum of the disease.