Founder Pathogenic Variant in LMNA and Its Diverse Phenotypic Manifestations in Mandibuloacral Dysplasia: Insights from a Turkish Cohort.

Objective: Mandibuloacral dysplasia (MAD) is a rare genetic disorder characterized by distinctive skeletal abnormalities, metabolic issues, and skin changes, often linked to pathogenic variants in the LMNA gene, which encodes lamin A/C. This study investigates a specific founder mutation within a Turkish cohort and explores its impact on phenotypic expressivity.

Methods: We conducted a comprehensive analysis involving genetic testing for LMNA variants in patients diagnosed with MAD. Clinical evaluations documented a wide range of phenotypic features, including facial dysmorphism, skeletal anomalies, and metabolic abnormalities. We also collected family histories to assess inheritance patterns and potential environmental influences.

Results: Our findings identified a common founder mutation in the LMNA gene among the cohort, which was present in a significant percentage of participants. Notably, phenotypic expressivity varied significantly, with some individuals exhibiting classic MAD features, while others showed atypical manifestations, such as additional endocrine disorders and variable severity of skeletal anomalies. This variability underscores the complexity of the genotype-phenotype relationship.

Conclusion: This study highlights the significance of the founder mutation in LMNA and its diverse phenotypic outcomes in MAD. Our results contribute to the understanding of how genetic mutations can lead to a spectrum of clinical presentations, emphasizing the necessity for personalized clinical approaches in managing this condition. Further research is warranted to elucidate the underlying mechanisms of phenotypic variability and to improve diagnostic and therapeutic strategies.