Potential Impact of Parental Origin of Inheritance on the Clinical Presentation of Familial Partial Lipodystrophy Type 2 Syndrome.

Context: Familial partial lipodystrophy type 2 (FPLD2) is a rare autosomal dominant disorder caused by pathogenic variants in the LMNA gene. The influence of parental inheritance on clinical presentation has not been fully explored.

Objective: To investigate the influence of maternal versus paternal inheritance of LMNA variants on the clinical and metabolic phenotype of patients with FPLD2.

Design, patients, measurements: This retrospective cohort study included 83 patients with FPLD2 from four different centres. Clinical, biochemical, and body composition data were analysed. Patients were grouped based on maternal (maternal inheritance group; n = 49) or paternal (paternal inheritance group; n = 34) inheritance of LMNA variants. Statistical comparisons were made between the groups.

Results: Patients in the maternal inheritance group had a younger current age (35 (33) vs. 48 (22) years, p = 0.042) and earlier diagnosis of lipodystrophy (22 (30) vs. 36 (25) years, p = 0.044) compared to those in the paternal inheritance group. Body fat percentages in the arms (23.8 (6.5) % vs. 21.0 (6.2) %, p = 0.034) and trunk (32.1 (10.3) % vs. 28.5 (6.1) %, p = 0.024) were higher in maternal inheritance group. Fatty liver disease (79% vs. 57%, p = 0.029) and pancreatitis (26% vs. 8%, p = 0.033) were more prevalent in paternal inheritance group.

Conclusion: Parental lineage may influence the phenotype of FPLD2: patients with a maternally inherited LMNA variant tend to preserve more adipose tissue in the upper body, while those with a paternally inherited variant experience greater adipose tissue loss in that region, often associated with more severe metabolic complications. These findings highlight the importance of contemplating parental lineage as a relevant factor when evaluating the clinical presentation and management of patients with FPLD2.