DMD and West syndrome

Epilepsy in dystrophinopathies: A retrospective cohort and review of the literature

OBJECTIVE

This study aimed to assess the prevalence and characteristics of epilepsy in dystrophinopathies within a cohort of 142 patients at a tertiary neuromuscular center in Istanbul, Turkey.

METHODS

We recorded the age at seizure onset, seizure type, family history, history of febrile seizures, treatment, and EEG results. Epilepsy was classified according to the latest International League Against Epilepsy (ILAE) classification.

RESULTS

Of the 142 DMD patients, 8 experienced epileptic seizures (5.6 %). The median age of the patients was 11 years (8.0-15.2). The median age for the first DMD symptoms was 24 months (16.5-37.5). All seizures were consistent with generalized tonic-clonic seizures. Three patients are currently on anti-seizure medication.

SIGNIFICANCE

The prevalence of epilepsy in our study (5.6 %) exceeds that of the general pediatric population (0.5-1 %). However, the frequency of febrile seizures in children with dystrophinopathy is similar to that of the general population.

Synaptic alterations as a neurodevelopmental trait of Duchenne muscular dystrophy

Dystrophinopaties, e.g., Duchenne muscular dystrophy (DMD), Becker muscular dystrophy and X-linked dilated cardiomyopathy are inherited neuromuscular diseases, characterized by progressive muscular degeneration, which however associate with a significant impact on general system physiology. The more severe is the pathology and its diversified manifestations, the heavier are its effects on organs, systems, and tissues other than muscles (skeletal, cardiac and smooth muscles). All dystrophinopaties are characterized by mutations in a single gene located on the X chromosome encoding dystrophin (Dp427) and its shorter isoforms, but DMD is the most devasting: muscular degenerations manifests within the first 4 years of life, progressively affecting motility and other muscular functions, and leads to a fatal outcome between the 20s and 40s. To date, after years of studies on both DMD patients and animal models of the disease, it has been clearly demonstrated that a significant percentage of DMD patients are also afflicted by cognitive, neurological, and autonomic disorders, of varying degree of severity. The anatomical correlates underlying neural functional damages are established during embryonic development and the early stages of postnatal life, when brain circuits, sensory and motor connections are still maturing. The impact of the absence of Dp427 on the development, differentiation, and consolidation of specific cerebral circuits (hippocampus, cerebellum, prefrontal cortex, amygdala) is significant, and amplified by the frequent lack of one or more of its lower molecular mass isoforms. The most relevant aspect, which characterizes DMD-associated neurological disorders, is based on morpho-functional alterations of selective synaptic connections within the affected brain areas. This pathological feature correlates neurological conditions of DMD to other severe neurological disorders, such as schizophrenia, epilepsy and autistic spectrum disorders, among others. This review discusses the organization and the role of the dystrophin-dystroglycan complex in muscles and neurons, focusing on the neurological aspect of DMD and on the most relevant morphological and functional synaptic alterations, in both central and autonomic nervous systems, described in the pathology and its animal models.

Third case of Duchenne muscular dystrophy and West syndrome: Expanding the spectrum of the DMD neuropsychiatric phenotype

Duchenne muscular dystrophy is an X-Linked neuromuscular disorder, and the most common muscular dystrophy. Neuropsychiatric phenotype associated to DMD gene mutations include now low IQ scores, epilepsy, autism, and attention deficit disorder. These have been observed with higher frequency in mutations that disrupt the short isoforms Dp71 and Dp140. West syndrome has been previously reported in two unrelated patients with Duchenne muscular dystrophy. Here, we report the third patient with West syndrome who had a novel hemizygous nonsense pathogenic variant in the exon 8 of the DMD gene c.811C>T, p.(Gln271*), suggesting West syndrome as part of the neuropsychiatric spectrum in Duchenne muscular dystrophy.

The expanding spectrum of dystrophinopathies: HyperCKemia to manifest female carriers

Background:

X-linked dystrophinopathies have a wide spectrum of manifestation. The most common forms are severe Duchenne muscular dystrophy (DMD) and Becker’s muscular dystrophy (BMD). However, less common manifestations are isolated cardiomyopathy, myalgia, cramps, rhabdomyolysis, hyperCKemia, and manifest female carriers.

Materials and Methods:

This case series is a part of an ongoing long-term prospective cohort of children with DMD and BMD from the year 2013. The clinical details are maintained in the clinic files and standard management protocols are followed. For this case series, clinical details were collected from the clinic files and recorded on a case record proforma. Details of cardiology, radiology, and genetic investigations were collected.

Results:

We report cases of classical DMD, BMD, manifest female carrier with proximal pelvic girdle weakness, a female carrier with isolated dilated cardiomyopathy, and infantile-onset asymptomatic hyperCKemia. We also report less common but notable clinical presentations of DMD, autism, intellectual disability, epilepsy, and asymptomatic transaminitis.

Conclusions:

It is important for clinicians to be aware of these less common clinical presentations for prompt diagnosis, and to avoid unnecessary investigations. Here, we report the clinical spectrum of dystrophinopathies seen in pediatric neuromuscular clinic and emphasize the variability and expanding knowledge about different manifestations of dystrophinopathies.

Early Identification of DMD in the Setting of West Syndrome

Duchene muscular dystrophy (DMD) is the most common muscular dystrophy in childhood, affecting ∼1:5000 male live births worldwide. DMD is a genetic disorder with X-linked recessive inheritance pattern characterized by a severe muscular phenotype with progressive muscle weakness and atrophy due to pathogenic variations within the DMD gene. Two cases are reported to date in the literature of individuals with a diagnosis of both DMD and West syndrome; neither of which had the degree of additional genetic abnormalities that our patient demonstrates. We present a male infant with West syndrome, and multiple pathogenic variants, the ominous one being in the DMD gene. This case adds to confirming that West syndrome expands the spectrum of epilepsy that may be present in DMD patients. Additionally, this case can identify how the early use of steroids may shed light on effects of early symptomatic treatment of DMD.