P76-F DYNC1H1 gene mutation in an Estonian family

Background DYNC1H1 gene mutations have been related to many neuromuscular diseases, including autosomal dominant Charcot-Marie-Tooth disease type 2O and autosomal dominant spinal muscular atrophy, with lower extremity predominance (SMA-LED). SMA-LED is a disease with large clinical variability. The early clinical signs are feet deformities, delayed walking and muscle weakness. Material and methods We will present the case report with EMG findings of the family with SMA-LED confirmed by genetic analysis. Results The diagnosis was confirmed with TrueSight One panel covering 4813 genes. Mutation M_001376.4(DYNC1H1):c.1869C > G p.Phe623Leu in DYNC1H1 gene was detected in mother and in two younger children of the family. Conclusion When EMG examination shows neurogenic changes and signs of spinal atrophy, but SMN1 gene test is negative, then it is important to think about rare forms of spinal muscular atrophies.