Natural history of LAMA2 related dystrophies

*Correspondence: [e-mail].

Abstract

Background: LAMA2-related dystrophies (LAMA2-RD) represent a rare neuromuscular disorder with a wide spectrum of phenotype severity, ranging from mild to severe.

Objective: To establish disease natural history, we performed a cross-sectional study of LAMA2-RD through motor function and pulmonary tests.

Methods: Fourty-four individuals with LAMA2-RD were included and were evaluated through functional outcome measures (MFM32, RULM, goniometry and Forced Vital Capacity (FVC)).

Results: The most frequent phenotype presentation was non-ambulatory (N=36, 81.8%), while eight patients (18.2%) were able to walk. Non-ambulatory group presented a more severe progression of disease. Non-ambulatory patients had a 1.85% decrease in FVC/year, against 0.98%/year among ambulatory patients. In the non-ambulatory group, there was a 4.2% drop/year in MFM32-D2 domain (p<0.00001), a 2.6% drop/year in D3 domain (p<0.0001), and a 2.7% drop/year in the MFM32 global assessment (p<0.0001). However, the evaluation of upper limb function, in both groups, didn’t show statistically significant reduction. In the non-ambulatory group elbow and knee retractions worsened 3.22 degrees/year (p=0.00087) and 1.92 degrees/year, respectively. While those patients who acquired gait, elbow and knee retractions worsened 1.41 degrees/year (p=0.0003) and 1.95 degrees/year (p=0.01), respectively.

Conclusion: This study confirmed the progressive nature of LAMA2-RD, both in ambulant and non-ambulant patients. MFM32, FVC and goniometry were identified as promising outcome measures for natural history studies and clinical trials in LAMA2-RD.

 

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Publication History

Article published online:
12 May 2025