Congenital muscular dystrophy with intellectual disability and severe epilepsy

What it is

From: Orphanet

A rare, fatal, inborn error of metabolism disorder characterized by respiratory distress and severe hypotonia at birth, severe global developmental delay, early-onset intractable seizures, myopathic facies with craniofacial dysmorphism (trigonocephaly/progressive microcephaly, low anterior hairline, arched eyebrows, hypotelorism, strabismus, small nose, prominent philtrum, thin upper lip, high-arched palate, micrognathia, malocclusion), severe, congenital flexion joint contractures and elevated serum creatine kinase levels. Scoliosis, optic atrophy, mild hepatomegaly, and hypoplastic genitalia may also be associated.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal facial shape · Frequent (79-30%)

An abnormal morphology (form) of the face or its components.

Absent smooth pursuit · Frequent (79-30%)

A complete lack of the ability to track objects with the ocular smooth pursuit system, a class of rather slow eye movements that minimizes retinal target motion.

Absent speech · Frequent (79-30%)

Complete lack of development of speech and language abilities.

Cerebellar hypoplasia · Frequent (79-30%)

Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time.

Elevated circulating creatine kinase concentration · Frequent (79-30%)

The activity of creatine kinase in the blood circulation is above the upper limit of normal.

Epileptic encephalopathy · Frequent (79-30%)

A condition in which epileptiform abnormalities are believed to contribute to the progressive disturbance in cerebral function. Epileptic encephalaopathy is characterized by (1) electrographic EEG paroxysmal activity that is often aggressive, (2) seizures that are usually multiform and intractable, (3) cognitive, behavioral and neurological deficits that may be relentless, and (4) sometimes early death.

Failure to thrive · Frequent (79-30%)

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Generalized clonic seizure · Frequent (79-30%)

Generalized clonic seizure is a type of generalized motor seizure characterized by sustained bilateral jerking, either symmetric or asymmetric, that is regularly repetitive and involves the same muscle groups.

Generalized hypotonia · Frequent (79-30%)

Generalized muscular hypotonia (abnormally low muscle tone).

Generalized myoclonic seizure · Frequent (79-30%)

A generalized myoclonic seizure is a type of generalized motor seizure characterized by bilateral, sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus.

Global developmental delay · Frequent (79-30%)

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

Micrognathia · Frequent (79-30%)

Developmental hypoplasia of the mandible.

Myopathic facies · Frequent (79-30%)

A facial appearance characteristic of myopathic conditions. The face appears expressionless with sunken cheeks, bilateral ptosis, and inability to elevate the corners of the mouth, due to muscle weakness.

Osteopenia · Frequent (79-30%)

Osteopenia is a term to define bone density that is not normal but also not as low as osteoporosis. By definition from the World Health Organization osteopenia is defined by bone densitometry as a T score -1 to -2.5.

Other findings in the same source

From: Orphanet

Additional reported features include Poor head control (Frequent (79-30%)); Progressive microcephaly (Frequent (79-30%)); Scoliosis (Frequent (79-30%)); Type I transferrin isoform profile (Frequent (79-30%)); Contractures of the large joints (Frequent (79-30%)); Abnormal periventricular white matter morphology (Occasional (29-5%)); Cerebral white matter atrophy (Occasional (29-5%)); Deep philtrum (Occasional (29-5%)); Dental malocclusion (Occasional (29-5%)); EEG with burst suppression (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Infancy; Neonatal

Inheritance in the source

From: Orphanet

Autosomal recessive

Frequency and the population described

From: Orphanet

Reported case(s): 3.0; Worldwide. This is a published case count, not prevalence. Point prevalence: <1 / 1 000 000; Worldwide; Class only.

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal recessive pattern usually involves disease-causing changes in both copies of a gene. Parents may each carry one altered copy without having the condition themselves. A genetic counsellor can explain carrier testing and reproductive implications using the actual laboratory findings, rather than the condition name alone.

Which doctor should you see?

The suggested department for discussing Congenital muscular dystrophy with intellectual disability and severe epilepsy is Metabolic Medicine, with a metabolic specialist / clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with metabolic specialist / clinical geneticist referral.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Is a biochemical or molecular result needed to clarify the diagnosis?
• Does this condition require an individual plan for illness or reduced food intake?
• Should nutrition advice come from a specialist metabolic dietitian?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Congenital muscular dystrophy with intellectual disability and severe epilepsy. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.