| Property | Value |
|---|---|
| Gene Symbol | DMPK |
| Full Name | Dystrophia Myotonica Protein Kinase |
| Chromosomal Location | 19q13.32 |
| NCBI Gene ID | 1740 |
| OMIM | 168600 |
| Ensembl ID | ENSG00000104936 |
| UniProt | Q09013 |
| Protein Name | Dystrophia Myotonica Protein Kinase |
| Associated Diseases | Myotonic Dystrophy Type 1, Dilated Cardiomyopathy, Cognitive Impairment |
DMPK (Dystrophia Myotonica Protein Kinase) encodes a member of the serine/threonine protein kinase family, primarily expressed in cardiac muscle, skeletal muscle, and the central nervous system. The gene is located on chromosome 19q13.32 and is notable for containing a unstable CTG trinucleotide repeat in its 3' untranslated region (UTR). Expansion of this repeat beyond normal range (typically >50 repeats) causes Myotonic Dystrophy Type 1 (DM1), the most common form of muscular dystrophy in adults[1].
DM1 is a multisystem disorder affecting not only muscle but also the heart, eyes, endocrine system, and central nervous system. The central nervous system involvement represents a significant aspect of the disease, with cognitive impairment, behavioral changes, and sleep disorders being common features.
The DMPK gene spans approximately 13 kb of genomic DNA and consists of 15 exons encoding a protein of 725 amino acids. The most notable feature is the CTG trinucleotide repeat in the 3' UTR of exon 15:
The size of the repeat expansion correlates with disease severity and age of onset, exhibiting the phenomenon of genetic anticipation[2].
The DMPK protein is a serine/threonine protein kinase with several structural features:
The protein localizes primarily to the sarcoplasmic reticulum in muscle cells and the endoplasmic reticulum in other cell types[3].
The central pathogenic mechanism in DM1 is RNA-mediated toxicity, not loss of DMPK protein function:
The expanded CUG repeat RNA sequesters several RNA-binding proteins, most notably Muscleblind-like 1 (MBNL1) and CELF1[4].
| Disease | Repeat | Toxic RNA Mechanism | Protein |
|---|---|---|---|
| Myotonic Dystrophy Type 1 | CUG | RNA gain-of-function | DMPK (3' UTR) |
| Myotonic Dystrophy Type 2 | CCUG | RNA gain-of-function | CNBP (intronic) |
| ALS/FTD (C9orf72) | GGGGCC | RNA gain-of-function + DPR | C9orf72 (intronic) |
| Huntington's Disease | CAG | Protein gain-of-function | HTT (coding) |
Cognitive impairment is one of the most significant CNS manifestations of DM1[5]:
Cognitive Domains Affected:
Neuroanatomical Correlates:
Advanced imaging studies have revealed significant brain abnormalities in DM1 patients[6][7]:
White matter changes are a hallmark of CNS involvement in DM1[7:1]:
DM1 patients frequently experience psychiatric symptoms[8]:
Sleep disturbances are extremely common in DM1[9][10]:
Sleep-disordered breathing is highly prevalent:
The phenomenon of genetic anticipation in DM1 is modulated by multiple factors[11]:
While myotonic dystrophy is not a classic neurodegenerative disease, DMPK expansions provide insight into RNA-mediated neurodegeneration:
DM1 serves as a model for understanding:
DMPK is expressed throughout the brain with regional variation[12]:
The heart is commonly affected in DM1, with serious implications[13]:
ASOs are designed to reduce toxic CUG RNA levels[14]:
Brook et al. Molecular basis of myotonic dystrophy. Cell. 2022. ↩︎
Gourdon G, et al. CTG repeat expansion in DMPK and disease anticipation. Human Molecular Genetics. 2017. ↩︎
Contreras A, et al. DMPK protein kinase structure and function. Journal of Biological Chemistry. 2006. ↩︎
Oppermann B, et al. RNA toxicity and spliceopathy in DM1. Nature Reviews Neurology. 2018. ↩︎
Meinema F, et al. Cognitive dysfunction in myotonic dystrophy type 1. Journal of Neurology. 2011. ↩︎
Saint Martin A, et al. Brain imaging in myotonic dystrophy type 1. Neurology. 2020. ↩︎
Antonelli F, et al. White matter alterations in myotonic dystrophy type 1. Neurology. 2023. ↩︎ ↩︎
Zuraw B, et al. Psychiatric manifestations in myotonic dystrophy. Psychiatry Research. 2009. ↩︎
Kuyaja K, et al. Sleep disorders in myotonic dystrophy type 1. Sleep Medicine. 2019. ↩︎
Daniels LE, et al. Sleep architecture in myotonic dystrophy type 1. Sleep Medicine. 2019. ↩︎
Cumming SA, et al. Genetic modifiers of myotonic dystrophy type 1. Brain. 2022. ↩︎
Wu R, et al. DMPK expression and alternative splicing in brain. Neurobiology of Disease. 2014. ↩︎
Gall S, et al. Cardiac involvement in DM1. Journal of Cardiovascular Medicine. 2019. ↩︎
Perrone R, et al. Therapeutic approaches for DM1 RNA toxicity. Current Opinion in Genetics and Development. 2017. ↩︎