Loading…
New phenotype of DCTN1‐related spectrum: early‐onset dHMN plus congenital foot deformity
Objective To describe the clinical and genetic features of two patients with different phenotypes due to various Dynactin 1 (DCTN1) gene mutations and further explore the phenotype–genotype relationship. Methods Patient 1 is a 23‐year‐old man with congenital foot deformity and life‐long distal muscl...
Saved in:
Published in: | Annals of clinical and translational neurology 2020-02, Vol.7 (2), p.200-209 |
---|---|
Main Authors: | , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Objective
To describe the clinical and genetic features of two patients with different phenotypes due to various Dynactin 1 (DCTN1) gene mutations and further explore the phenotype–genotype relationship.
Methods
Patient 1 is a 23‐year‐old man with congenital foot deformity and life‐long distal muscle weakness and atrophy. Patient 2 is a 48‐year‐old woman with adult‐onset progressive weakness, lower limbs atrophy, and pyramid bundle signs. Electrophysiology test showed normal nerve conduction velocity of both patients and neurogenic changes in needle electromyography. Open sural nerve biopsy for Patient 1 showed slight loss of myelinated nerve fibers. Both patients were performed with whole‐exome sequencing followed by functional study of identified variants.
Results
Two mutations in DCTN1 gene were identified in Patient 1 (c.626dupC) and Patient 2 (c.3823C>T), respectively. In vitro, the wild type mostly located in cytoplasm and colocalized with α‐tubulin. However, c.626dupC tended to be trapped into nuclear and the c.3823C>T formed cytoplasmic aggregates, both losing colocalization with α‐tubulin. Western blotting showed a truncated mutant with less molecular weight of c.626dupC was expressed.
Interpretation
We identify two novel DCTN1 mutations causing different phenotypes: (1) early‐onset distal hereditary motor neuropathy plus congenital foot malformation and (2) amyotrophic lateral sclerosis, respectively. We provide the initial evidence that foot developmental deficiency probably arises from subcellular localizing abnormality of Dynactin 1, revealing DCTN1‐related spectrum is still expanding. |
---|---|
ISSN: | 2328-9503 2328-9503 |
DOI: | 10.1002/acn3.50985 |