Familial dilated cardiomyopathy with conduction defect due to LMNA mutation

What it is

From: Orphanet

A rare familial cardiomyopathy characterized by left ventricular enlargement and/or reduced systolic function preceded or accompanied by significant conduction system disease and/or arrhythmias including bradyarrhythmias, supraventricular or ventricular arrhythmias. Disease onset is usually in early to mid-adulthood. Sudden cardiac death may occur and may be the presenting symptom. In some cases, it is associated with skeletal myopathy.

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.

Cardiac conduction abnormality · Very frequent (99-80%)

Any anomaly of the progression of electrical impulses through the heart.

Dilated cardiomyopathy · Very frequent (99-80%)

Dilated cardiomyopathy (DCM) is defined by the presence of left ventricular dilatation and left ventricular systolic dysfunction in the absence of abnormal loading conditions (hypertension, valve disease) or coronary artery disease sufficient to cause global systolic impairment. Right ventricular dilation and dysfunction may be present but are not necessary for the diagnosis.

Abnormal left ventricular function · Frequent (79-30%)

Inability of the left ventricle to perform its normal physiologic function. Failure is either due to an inability to contract the left ventricle or the inability to relax completely and fill with blood during diastole.

Abnormal myocardium morphology · Frequent (79-30%)

A structural anomaly of the muscle layer of the heart wall.

Atrial fibrillation · Frequent (79-30%)

An atrial arrhythmia characterized by disorganized atrial activity without discrete P waves on the surface EKG, but instead by an undulating baseline or more sharply circumscribed atrial deflections of varying amplitude an frequency ranging from 350 to 600 per minute.

Lipodystrophy · Frequent (79-30%)

Degenerative changes of the fat tissue.

Sudden cardiac death · Frequent (79-30%)

The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset).

Syncope · Frequent (79-30%)

A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion.

Abnormal lymphocyte physiology · Occasional (29-5%)

Any anomaly of lymphocyte function.

Atrial flutter · Occasional (29-5%)

A type of atrial arrhythmia characterized by atrial rates of between 240 and 400 beats per minute and some degree of atrioventricular node conduction block. Typically, the ventricular rate is half the atrial rate. In the EKG; atrial flutter waves are observed as sawtooth-like atrial activity. Pathophysiologically, atrial flutter is a form of atrial reentry in which there is a premature electrical impulse creates a self-propagating circuit.

Congestive heart failure · Occasional (29-5%)

The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction.

Heart block · Occasional (29-5%)

Impaired conduction of cardiac impulse occurring anywhere along the conduction pathway.

Muscular dystrophy · Occasional (29-5%)

The term dystrophy means abnormal growth. However, muscular dystrophy is used to describe primary myopathies with a genetic basis and a progressive course characterized by progressive skeletal muscle weakness and wasting, defects in muscle proteins, and histological features of muscle fiber degeneration (necrosis) and regeneration. If possible, it is preferred to use other HPO terms to describe the precise phenotypic abnormalities.

Pericardial effusion · Occasional (29-5%)

Accumulation of fluid within the pericardium.

Other findings in the same source

From: Orphanet

Additional reported features include Sinoatrial block (Occasional (29-5%)); Supraventricular tachycardia (Occasional (29-5%)); Ventricular arrhythmia (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Adult

Inheritance in the source

From: Orphanet

Autosomal dominant

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal dominant pattern means that one altered copy of a relevant gene can be sufficient for the condition. Some affected people inherit the change; others have a new change without an affected parent. The precise finding, family history and condition determine what this means for relatives.

Which doctor should you see?

The suggested department for discussing Familial dilated cardiomyopathy with conduction defect due to LMNA mutation is Cardiology, with a cardiologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

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 the main concern heart structure, rhythm, circulation or another cause?
• Which symptoms should change the timing of follow-up?
• How would a proposed investigation change the care plan?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Familial dilated cardiomyopathy with conduction defect due to LMNA mutation. 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.